Islamic State militants have released a video that shows the beheading of a US journalist who went missing two years ago.
The footage shows a masked man - speaking in English with an English accent - killing James Foley, who was seized by armed men in Syria in November 2012.
In the five-minute propaganda video, posted on social media sites by Islamic State sources, the man says Mr Foley was being killed because Barack Obama had ordered airstrikes against IS positions in northern Iraq.
Just hours after the video was released, a US official said American drones had carried out nearly a dozen airstrikes in Iraq since Tuesday.
The journalist, dressed in an orange jumpsuit like those worn by Guantanamo inmates, is seen kneeling in the desert before he blames the US for his death, in a statement presumably prepared by his abductors.
He then says "I wish I had more time, I wish I could have the hope of freedom and seeing my family once again, but that ship has sailed." He is then beheaded.
The group also claimed to be holding another American journalist, Steven Sotloff, who appears at the end of the video, and said his life depended on the US President's next move.
Mr Foley's family is begging people not to watch the video showing him being murdered.
The Metropolitan Police in Britain say viewing or downloading the contents of the video could be considered criminal.
It says in a statement "We would like to remind the public that viewing, downloading or disseminating extremist material within the UK may constitute an offence under Terrorism legislation."
"We have never been prouder of our son"
A statement issued by Mr Foley's mother, Diane Foley, said "We have never been prouder of our son, Jim. He gave his life trying to expose the world to the suffering of the Syrian people."
"We implore the kidnappers to spare the lives of the remaining hostages. Like Jim, they are innocents. They have no control over American government policy in Iraq, Syria or anywhere in the world."
"We thank Jim for all the joy he gave us. He was an extraordinary son, brother, journalist and person. Please respect our privacy in the days ahead as we mourn and cherish Jim," she added.
Diane Foley's statement on Facebook
Mr Foley (40) was an experienced correspondent who had covered the war in Libya before heading to Syria to follow the revolt against Bashar al-Assad for the GlobalPost, AFP and other outlets.
Philip Balboni, GlobalPost chief executive and co-founder, said the firm had been informed that the FBI is evaluating the video to determine whether it was authentic.
"We ask for your prayers for Jim and his family," he said.
According to witnesses, Mr Foley was seized in the northern Syrian province of Idlib on November 22nd in 2012. The car he was travelling in was stopped by four militants in a contested battle zone that both Sunni rebel fighters and government forces were trying to control.
Several senior US officials with direct knowledge of the situation told the Associated Press that IS very recently threatened to kill Mr Foley to avenge the American airstrikes over the last two weeks.
The strikes targeted militants advancing on Mount Sinjar, the Mosul Dam and Kurdish capital Irbil.
The release of the video comes a day after IS militants threatened to attack US targets in another video where they warned "we will drown all of you in blood."