overthrown by muslim rebels, sparking long-running fighters between his supporters, known as the anti-balaka and the seleka fighters. they have been struggling to stop the fighting, forcing more than 400,000 from their homes. the latest fighting comes weeks before a presidential election. we have this report. >> reporter: the u.n. is not welcome in parts of bangui, all day on tuesday residents put up roadblocks to keep peacekeepers out of their neighbourhoods. and u.n. troops kept taking them down. >> translation: the population is desperate and doesn't believe in the forces any more. >> translation: no, we want the departure of international forces that do nothing. we want those that have committed crimes to be tracked down by the justice commission. >> a u.n. spokesman told al jazeera they could do more, but they are fully engaged. the spokesman said the u.n. is working with community leaders and government officials to put an end to violence in the capital. over the weekend, a muslim taxi driver was killed, setting off days of the fighting in the streets leaving 40 dead, and tens of thous

have troops and balaka.hey have killed at least 40 people >>> and president obama says he'll use all means available to defeat i.s.i.l., chairing a meeting on terrorism in new york. the u.s. president said it will be a long-term campaign. >> now, most world leaders today are using social media to get their message across. they have a huge presence on platforms like facebook, youtube and twitter. the 45 highest profile speakers have 100 million followers on twitter between them. president obama has 68 million at had@president obama act. the brazilian president has more than 4 million followers, and 3.5 million following the turkish prime minister. and the kenyan president has more than 1 million twitter followers. social media experts urge caution. shaun powers says followers can be brought, and what matters is the message politicians can get across with his tweets. >> there are services that for a relatively inexpensive fee will help you get thousands, if not million of followers. you see them climb the rank

what that means is that armed groups by the anti-balaka and seleka can tax the diamonds and companies aren't checking to make sure they're not buying conflict diamonds. they're currently stockpiled and banki, and we're saying that the government should be making companies check whether they have sold conflict diamond. if they can't prove they haven't, they should confiscate those diamonds and sell them for the public good. >> to take that point forward, it has to be said, of course, the companies mentioned in your report are saying this is nonsense. they don't do business with mines controlled by armed groups. nevertheless, you are saying that the government has a duty to confiscate any diamonds not properly bought? >> i think the problem is that if these companies can't provide reasonable evidence those diamonds are conflict diamonds, then the chances are they will get into international markets and end up with consumers. it seems wrong that those companies themselves should be able to profit from the diamonds. what we're looking for is the government to sell them and profit from the