>> narrator: tonight on frontlintwo reports from syria. first, an exclusive from the new battlefront where islamic extremists waving the al qaeda flag are trying to take over the country. >> the scene was horrific. these suicide bombs were going off almost every day. >> narrator: syrian journalist muhammad ali embeds with rebels fighting to drive the extremists out. >> i was the only journalist allowed in. >> narrator: for the first time on television, a rare look at syria's second front.

and in our second story tonight, the war has claimed more than 10,000 children. but for kids living with snipers and rubble all around them, this is their own story in their own words. through breathtaking photojournalism, a dramatic portrait of the children of aleppo. (singing) (explosion) these two stories, tonight on frontline. >> frontlineis made possible by contributions to your pbs station from viewers like you. thank you. and by the corporation for public broadcasting. major support for frontline is provided by the john d. and catherine t. macarthur foundation. committed to building a more just, verdant and peaceful world.

more information is available at macfound.org. additional funding is provided by the park foundation, dedicated to heightening public awareness of critical issues. the wyncote foundation. and by the frontline journalism fund, supporting investigative reporting and enterprise journalism. >> narrator: reporter muhammad ali is crossing into syria as a violent new phase of the civil war is beginning.

he is filming his journey into the north of the country under the protection of fighters from the free syrian army, who began the uprising against the regime of bashar al assad, but are now also battling radical islamic factions-- jihadists who want to take over the country. >> we have just crossed from the syrian borders with turkey. the jihadists don't like journalists. they don't like the fsa battalions because they are accusing them of being spies for the west. it's a very dangererous situation right now. >> narrator: muhammad and the rebels are picked up in a car and driven for seven hours through the night. >> the situation is not that good as before. new groups came and they start stealing the revolution. so it is very important for me to tell what's happening on the

ground. no western media can get in. >> narrator: he is taken to stay at a rebel base where a battalion has retreated after many of their comrades were killed fighting the jihadists. after losing ground to the jihadists in recent months, more moderate rebels are now coming together to fight back. muhammad is brought to a secret location for a heavily guarded meeting of opposition leaders. >> they were very worrd about the situation, concerned about suicide bombers. they checked my camera equipment, they checked my radio device, everything. they were asking me for who i am working. i was the only journalist.

>> narrator: this meeting was one of the first times the leaders of different factions, religious and secular, had met since the war began. it would turn out to be historic. >> over three years of my covering the civil war in syria i've seen the rebels getting more and more divided. so when i saw them coming together, it was very shocking. >> (translated): we've lost many men and shed a lot of blood. now even your own families who've lost loved ones are starting to give up. if we continue with this mentality, then i tell you from my point of view as a simple man, these faces are not the faces of victory. if we are able to join forces, then we can take a step forward. there is nothing more important than our cause and our land. and there is nothing bigger in history than our revolution.

>> narrator: the group agreed to unite behind a new leader, jamal marouf. >> he was one of the beginning leaders to lead this revolution. he was very famous and people like him. >> (translated): everyone, listen up, listen up. we're trying to build an army whether we like it or not. today we set up a structure for the military. what if the regime were to collapse? if the regime collapses, who's going to run the country? >> narrator: marouf would lead a new movement, called the syrian revolutionary front, to fight against the jihadists. >> (translated): we're ready to fight every group that behaves like the regime. and if a group wants to use weapons against us and fight us and their goal is to steal the syrian revolution, we will not hesitate to fight back.

>> narrator: a young fighter named hazem, who was a lieutenant in assad's army before defecting, has signed up his rebel battalion to the new syrian revolutionary front. he shows muhammad what they are up against. >> (translated): we're driving along these farm roads to avoid being attacked by the jihadists. the jihadists are more ruthless than assad's regime. they attack villages with artillery and shells. in that village they just killed 15 civilians, including women and children. they use mines and car bombs as if we are their main enemy. but they are the enemy of the revolution and for syria as a whole. >> narrator: the most radical of the jihadist factions to turn

against the other rebels is the islamic state of iraq and syria: isis. (machine gun fire) the group wants to establish an islamic state in syria. (loud cannonfire) it claims an alliance with al qaeda, but even al qaeda has severed ties with them. isis has been capturing towns all over the north, including the town of al-atareb, a crucial location in the war. >> if the jihadists control al-atareb town, the fsa will be stuck in the south between the jihadists in the north and the regime troops in the south.

so it was a very important moment. >> narrator: in november 2013, isis staged a show of strength in the town, parading a group of rebels captured in battle, including an fsa commander, hasan jazra. locals filmed it on their cellphones. (gunshots) (shouting)

>> narrator: muhammad persuades some of the rebels to sneak him into al-atareb. >> i was about to enter the town. the first thing i saw was a big flag of al qaeda. the only thing in my mind was that scene of seven fighters of the fsa were executed. i was sure if they catch me and they suspect me, i will be killed. >> narrator: in the town square, isis is holding a public rally where fighters are pledging allegiance to global jihad. muhammad wants to film it, but the rebels say it is too dangerous. so a local man agrees to film it for him.

>> we left the rally and the rebels were all worried. hazem told me, "if we are going to leave the situation like

this, all of us will be under their control." >> narrator: muhammad and the rebels have returned to their base just outside al-atareb. (explosion nearby) (men shouting on walkie-talkie)

>> the bomb went off at 2:00 a.m. we were thrown out of our beds. >> narrator: the next morning, the rebels show muhammad where an isis suicide bomber had blown himself up by a local farm. it destroyed houses and killed two of hazem's men. >> suicide bombs were going off almost every day. hazem told me he'd had enough.

>> narrator: later that day, hazem and the new rebel movement prepare to launch one of their first major attacks against isis. about tomorrow? >> (translated): yes, kind of. i'm thinking about how god is

going to help us win this battle. >> (translated): do you think it will be a difficult mission? >> (translated): isis is very tough. they are animals. they're not real muslims. >> narrator: the rebels tell muhammad that because they have not received military support from the west, they are relying on equipment captured in battle. (truck engine starts up) (applause) (equipment jangling)

>> (translated): whoever dies will go to heaven, god willing. just put in your head and heart that they are extremists. we're fighting them because they killed our families and our children. we have god on our side. >> (translated): the loot is for everyone. but remeber, looting should be the

least of your concerns. don't die a meaningless death. >> narrator: many of hazem's men are devout muslims, but they say isis are extremists who are distorting islam. before they go into battle, they are addressed by a young cleric. >> (translated): if isis declares themselves a state, then what will we have?

we will end up with a group of states fighting each other with hate being their only common denominator. these people are savages, not humans at all. >> narrator: hazem has 100 men in his unit, but he is one of the few with any military experience before the war. these were farmers, barbers, shopkeepers, ordinary working men who'd been fighting in a revolution that has turned into a war against islamic extremists.

>> narrator: hazem leads his men towards the isis base just outside al-atareb. he orders them to surround it. one of the fighters films the battle. (gunshots) >> narrator: a sniper covers the rebels as they advance. (artillery explosions)

>> narrator: hazem and his men move in. >> narrator: when they get inside, the base is empty. the surviving isis fighters have fled. (shouting victoriously) (celebratory gunfire)

>> (praying): allahu akbar... >> narrator: having taken the base, the rebel forces now had control of al-atareb. (siren wailing) >> (translated): just like we fought bashar, we fought isis. they're even worse than the regime. if we had waited to attack any longer, they could have controlled the whole country. once we finish with isis, we can return to fighting assad and deliver a serious blow to the regime. >> narrator: with isis gone, muhammad returned to al-atareb.

>> big moment, you know, to see people free again and speaking without any fears from anyone. (children laughing) >> (translated): since we were freed, we live in safety. their hobbies include sabotage, kidnap and murder in cold blood. the ones who pay for this are the weak civilians. only over our dead bodies will we hand the town back to isis.

>> narrator : he went back to isis headquarters where the seven rebels were executed. >> the slogans were still there, but the building was empty. (shouting) (gunshots echoing) >>it was eerie being back there. the town was still in the middle of a war, but life seemed almost normal.

>> coming up next on frontline , through the eyes of children. (gunfire) a startling portrait of everyday life in a warzone. (singing) (explosion) "children of aleppo" begins right now on frontline. ♪

(interviewer speaking arabic) >> narrator: farah lives with her three siblings: her older sister, helen, her younger sister, sarah, and her brother, mohammad. they live with their parents here in this middle-class suburb that is now a front line in syria's largest city, aleppo. some 200,000 residents have fled the brutal fighting. (speaking arabic)

(young woman speaking arabic)

(explosion nearby) >> narrator: the children's father, abu ali, was one of the first to join the rebel group, the free syrian army. (young man speaking arabic) (gunshots nearby)

>> narrator: abu ali commands a katiba, or battalion, of 300 fighters. they hold a strategic position on a hill overlooking the regime-controlled city center. daily, there are violent gun battles. (gunshots) (woman speaking arabic)

(gunshots) (man speaking arabic) (gunshots)

(explosion in the distance) >> narrator: mohammed sneaks through the front line to

explore his friend's home that's been almost totally destroyed by shelling.

>> narrator: just a short distance away, the rebels have tighter control and people can move more freely.

(people chanting) >> narrator: 12-year-old aboude is one of those demonstrators. he performs here almost every day. he was one of the first to lead protests at his school. (aboude singing) >> narrator: teachers reported him to the police and he was beaten for his defiance. now he's a well-known member of the local opposition, leading singing at peaceful street rallies. (crowd singing)

(singing continues) (woman speaking arabic) (singing)

(man speaking arabic) >> narrator: aboude's family worries he is a visible target. they say government spies infiltrate the rebel-held areas and kidnap protesters. those who have gone missing are often never seen again.

>> narrator: life here has dramatically changed. in parts, the city's almost a ghost town. homes abandoned during the fighting have become a place where the girls go exploring. >> hala:

>> narrator: most schools have been destroyed or closed. (singing)

>> helen:

>> narrator: aboude now spends most of his time at the demonstrations and protests. (chanting)

(singing) (explosion)

>> aboude: >> narrator: it's estimated the fighting has claimed the lives

of more than 10,000 children across syria. it has also separated friends. (explosion) (cheering) (explosion) (gunfire) (gunfire)

(chanting)

>> aboude: >> narrator: but now aboude's brother has gone missing. and his family fears he has been captured by islamic extremists.

>> helen: >> abu ali:

>> mohammed:

>> aboude: ♪

>> go to pbs.org/frontline. (chanting) learn more about the spread of isis inside syria. explore our full archive of films from the warzone. (crying) read a series of stories from our partners at mcclatchy. and connect to the frontline community. sign up for our newsletter and follow us on facebook, twitter and pbs.org/frontline. >> narrator next time on frontline... >> i like... >> i like... >> i like... >> narrator: the power of like. >> companies know how to turn like into money. >> narrator: the kids who are liked... >> this is my first bite of a cool ranch dorito taco. >> narrator: and the advertising machine spinning likes into gold.

>> your consumer is your marketer. >> this is the biggest transformation that we've had in our lifetime. >> narrator: inside "generation like." >> frontlineis made possible by contributions to your pbs station from viewers like you. thank you. and by the corporation for public broadcasting. major support for frontline is provided by the john d. and catherine t. macarthur foundation. committed to building a more just, verdant and peaceful world. more information is available at macfound.org. additional funding is provided by the park foundation, dedicated to heightening public awareness of critical issues. the wyncote foundation. and by the frontline journalism fund, supporting investigative reporting and enterprise

journalism. >> for more on this and other frontline programs, visit our website at pbs.org/frontline. >> frontline's "syria's second front" is available on dvd. to order, visit shoppbs.org or call 1-800-playpbs. frontline is also available for download on itunes. turn to pbs...

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two, four, six, eight, we don't want to integrate! two, four, six, eight, we don't want to integrate! [sirens wailing] (phylicia rashad, narrating) southern states fought the desegregation of public schools with massive resistance, and south carolina was the last to comply. but in 1963, harvey gantt integrated clemson college, peacefully. his success did not come without struggle. ♪ on january 28, 1963,