BBC News with Fiona MacDonald.

A video has been released on the Internet purporting to show the beheading of the US journalist Steven Sotloff by Islamic State militants. The video shows a masked figure with a knife standing over Mr Sotloff, who was abducted in Syria last year.

The jihadist also issued a threat against a British hostage and warned governments to end their alliance against IS. Barbara Plett Usher reports from Washington.

US officials said if the video was genuine they would be sickened and appalled by this brutal act taking another innocent American life. Islamic State had warned it would kill a second US journalist if Washington refused to stop air strikes against its fighters in Iraq. The video apparently highlights the failure of intense US efforts to free a number of American hostages still held by the extremists. None of the countries to which Washington has appealed for help seemed to have any influence on the group. It would also increase pressure on President Obama to go after the militants at their base in Syria,which he has been reluctant to do.

The United States Department of Defence has said it had targeted the leader of the Somali Islamist militant group al-Shabab in an air strike. A spokesman, Rear Admiral John Kirby, said it was unclear whether Ahmed Abdi Godane was killed in the attack though he said the targets had been hit.

"Yesterday at approximately 11:20 Eastern time, working from actionable intelligence, US special operations forces using manned and unmanned aircraft destroyed an encampment and a vehicle, using several Hellfire missiles and laser-guided munitions. This operation was a direct strike against the al-Shabab network. We are still accessing the results of the operation, and we will provide additional information when and if appropriate."

Members of al-Shabab have confirmed Godane was in one of the cars that were struck on Monday night.

The head of the international medical charity Medecins Sans Frontieres has told the United Nations the battle against the Ebola outbreak in West Africa is being lost. Joanne Liu said world leaders were failing to address the worst Ebola epidemic in history and said so few medical staff were available that some treatment centres were now places where patients went to die. The UN's coordinator for the response to the crisis David Nabarro said the world needed to do more.

"All we can do is to use every single capacity that we can find to get the necessary scale-up and search of the right responses so that this outbreak is brought back under control."

The US Secretary of State John Kerry is to meet Palestinian negotiators on Wednesday to discuss the ceasefire in Gaza. Chief negotiator Saeb Erekat is also due to call for a timetable to end Israel's occupation of the West Bank. Meanwhile Washington has restated its appeal to Israel to withdraw plans to appropriate Palestinian land in the West Bank.

BBC News.

There has been heavy shelling around the airport in Donetsk in eastern Ukraine. Civilians have been fleeing the area, but Ukrainian forces say they remain in control of the facility. Pro-Russian rebels have made gains in eastern Ukraine over the past week. Richard Galpin has the details.

Further fighting today around the airport near Donetsk city. The rebels spoiled by a series of victories in recent days now have this key airport in their sides. It's been an important base for Ukrainian troops for several months, but now it's believed those still there are increasingly isolated. The army has already pulled back from several other positions around the city. The rebels are now poised to regain much of the territory they've lost recently to the Ukrainian army.

The White House says Nato will discuss significantly increasing its readiness in eastern Europe as a result of the crisis in Ukraine. The plans will be debated at this week's alliance summit and are said to involve training, exercises and other needs of eastern member states. Moscow said earlier it was beefing up its military strategy because of Nato plans to deploy a rapid reaction force in the countries.

Rescue teams in Nicaragua have suspended their efforts to locate seven gold miners trapped in a landslide five days ago. The Nicaraguan government says the landslide had made it unsafe for the work to proceed. Twenty two men have been rescued with minor injuries since the accident on Thursday.

An investigation by computer giant Apple into the hacking of private nude photos of celebrities has revealed that some accounts were compromised in what the company calls a "targeted attack". Apple said they had found no sign of a breach in its iCloud storage system. It rather discovered that user names, passwords and security questions had been targeted by hackers.

BBC News.