Islamic State group holding US woman as hostage
The Islamic State (IS) militant group is holding hostage a young American woman who was carrying out humanitarian aid work in Syria, it has emerged.
The 26-year-old woman is the third American known to have been kidnapped by the radical group.
The group recently threatened to kill American hostages to avenge the crushing air strikes in Iraq against militants advancing on Mount Sinjar and the Kurdish capital of Irbil.
The woman was captured last year while working with three humanitarian groups in Syria. A representative for her family and US officials asked that she not be identified out of fear for her safety.
More than a week ago American freelance journalist James Foley was beheaded by IS, which kidnapped him in November 2012. Mr Foley, 40, had worked in a number of conflict zones across the Middle East, including Iraq, Libya and Syria.
He was in northern Syria on assignment for Agence France-Press and the Boston-based news organisation GlobalPost when the car he was in was stopped by four militants in a contested battle zone both Sunni rebel fighters and government forces were trying to control.
The IS video of Mr Foley's beheading also showed another of the missing American journalists, Steven Sotloff, and warned he would be killed next if US air strikes continued. US officials believe the video was made days before its release and have grown increasingly worried about Mr Sotloff's fate.
Other American hostages have been held by militant groups, including Peter Curtis, who was recently released by al-Nusra Front, a rival Sunni extremist group. Another US freelance journalist, Austin Tice, disappeared in Syria in August 2012 and is believed to be held by the Syrian government.
Mr Tice was working for The Washington Post, McClatchy Newspapers and other media outlets when he was kidnapped.
The IS group is seeking to create a caliphate across parts of Syria and Iraq. It is so ruthless in its attacks against all people they consider heretics or infidels that it has been disowned by al Qaida's leaders.
In a speech in North Carolina, President Barack Obama said "America does not forget" and vowed justice for Mr Foley's murder.
In its annual report last November, the New York-based Committee to Protect Journalists estimated at least 30 had been kidnapped or had disappeared in Syria - held and threatened with death by extremists or taken captive by gangs seeking ransom.
The CPJ described the widespread seizure of journalists as unprecedented and largely unreported by news organisations in the hope that keeping the kidnappings out of public view may help to negotiate the captives' release.
The group said 52 journalists had been killed since Syria's civil war began in early 2011 and documented at least 24 others who disappeared earlier this year but are now safe.
Separately, the Paris-based Reporters Without Borders last year cited higher figures, saying at least 60 "news providers" were being detained and more than 110 had been killed.