BBC News with Maria Marshall.

The director of the FBI James Comey says the bureau has identified the masked Islamic State militant who carried out the recent beheadings of two US journalists and a British aid worker. Mr. Comey said the killer was identified with the help of international partners. Ali McBull reports from Washington.

The FBI director James Comey didn't reveal his name or nationality, but said the man video-taped apparently murdering American and British hostages has now been identified. Officials in the UK have recently said the man appeared to be British. The same militant has now appeared in several tapes released by the extremists group ISIS. In the most chilling, he stands beside the hostages, the British aid worker David Haines, the American journalists James Foley and Steven Sotloff before taking a knife to their throats.

The United States has said it's too early to say that the coalition it's leading is winning the fight against the Islamic State militants. The Defense Department said that even after the hit the Islamic State has taken, they had access to finance, weapons and volunteers. The airstrikes against the militants have continued in both Syria and Iraq with planes targeting vehicles, check points and command posts. Youlan Nail has been speaking to Syrian Kurds on the Turkish boarder.

The YPG, the Kurdish militia that operates in that area says it has been reinforced by Kurds from Turkey coming in as well and says it has managed to halt the IS advance. And that does give a lot of encouragement to Iraqi Kurds that you speak to. And now they are very keen to have more military help from the Americans, from British. This air power is helping them on the grounds but obviously you see a kind of holding passing here: They haven't managed to win back really big strategic gains from IS at this stage.

Iranian president Hassan Rouhani has alleged that strategic blunders by Western countries in the Middle East have turned it into a heaven for terrorists. Mr. Rouhani told world leaders at the UN General Assembly that certain states and intelligence agencies had, he said, put blades in the hands of mad men who now spared no one.

Scientists say at least 500 million computers could be at risk from a newly discovered bug which could make them vulnerable to remote cyber attacks. The flaw which has been dubbed Shellshock has been found in software in popular operating systems such as Linex and Apple's Mac operating system. Professor Alan Woodward is a security researcher from the University of Surrey.

It's been included in the past 25 years in all sorts of systems that run on Linex and indeed all sorts of imbedded systems that people probably don't realize are running. There is the software, like their WIFI routers, online disk drives, things like that. The upshot of it is it allows people to potentially run their own code or bits of programming remotely on your computer.

You are listening to the latest World News from the BBC.

Suspected militants from the Boko Haram group have attacked the town of Shafa in northeastern Nigeria, killing at least 18 people. Eyewitnesses said the assault began late on Wednesday and continued until Thursday morning. The Islamists are also said to have destroyed a number of churches and Christian homes in the town and attacked a nearby village.

President Obama says West Africa faces a humanitarian catastrophe unless the world moves more quickly to stop the Ebola outbreak. Mr. Obama said nations need to commit more air transport, care workers and medical equipments.

How fast we can arrest the spread of this disease is within our control and if we move fast even if imperfectly, then that could mean the difference between 10,000, 20,000, 30,000, that's versus hundreds of thousands or even a million deaths.

The police chief of Ferguson in the US State of Missouri, has apologized to the family of Michael Brown, the unarmed black teenager who was shot dead by a police officer in the city last month, a killing which sparked days of violent street clashes. In a video statement, Chief Thomas Jackson said he regretted the fact that officers had allowed Mr. Brown's body to lie in the street for four hours after he was shot.

The authorities in the United States have granted permission to six television and movie companies to use drones to shoot film scenes. The Federal Aviation Administration loosened previously tight restrictions on the commercial use of unmanned aircraft and would allow the six firms to fly drones, providing they don't compromise their safety.

Moscow has sent a female cosmonaut into space for the first time in 17 years. Elena Serova is only the forth Russian or Soviet woman in space. She and two male colleagues blasted off from the Baikonur Cosmodrome in Kazakhstan to take over at the International Space Station.

BBC News.