we've seen the men in balaclavas, who we assume are special forces, we've seen presumably the army walking around in green, and there's the swot team all heavily armed. france has had a good opportunity to train for these kind of operations with events that we've seen happening after charlie hebdo. >> there's the acts in 1990. i remember a plane that was stationed from algeria that were able to take - eight terrorists inside the plane. the question now is what is happening right now inside this apartment, if indeed there's still one person being detained, i don't know what medical condition is, but the idea is to get to him >>> presumably they're not going straight in because there's other factors at play here. maybe there's a hostage, maybe there's explosives, maybe their buildings are booby trapped. >> this is a very dense neighborhood. the operation being able to operate and trying to contain potential people wanting to go close to it. i imagine since the operation started very early in the morning, there are still people nearby, whether they were taken out of the scene or whatever. it

first the police roll in, then we saw the counterterrorism forces, men armed to the teeth wearing balaclava, ski masks, running towards the scene. we saw army trucks piled with soldiers spilling out into the street, taking up positions and anybody who comes near these officers is being pointed away, not with their hand but with a weapon. this is still very serious and all the people that are still on the other side of the perimeter are caught when they go out of their homes, out of their apartments, we've seen them have their hands on their head, trying to be the least threatening as possible because, again, officers aren't sure exactly of who might be involved in these terrorist actions and who exactly might be a threat to them. so, significant concern here still. it seems like the bulk of the operation is over, maybe there's some mop-up action going on still, but very, very tense here on the streets of paris. >> and that we know as early as tuesday, both french and american intelligence believed that the mastermind behind this attack was inside syria. we also know inside of france there w

about 30 police officers in multiple cars and vans, some of those police officers dressed in black balaclavaso conceal their faces, and they staged a raid on an apartment building, we were kept behind a police cordon, and couldn't see whether any people were arrested or property seized. and now police are saying they are not commenting about ongoing police operations, but that certain is a sign that very much the hunt for salah abdeslam is on the go. what we don't fully know at this stage in the investigation is what role that young man played in the paris operations. yes, we do know from police and prosecutors that he rented a feek that apparently -- vehicle that apparently ferried one or two of the attackers down to paris and around paris, but we don't know if he was a gunmanar whether he, himself, planned to be a suicide bomber, and whether something failed. essentially when he fled to brussels, is this the plan b. given that he's managed to elute a man hunt for four days, it seems he had a lan in place -- plan in place. >> a brother of salah abdeslam was one of the attackers that died. an