A secret, failed mission by the United States military to rescue American hostages, including the murdered journalist James Foley, has been described in full to the Daily Telegraph.
Two dozen Delta Force commandos landed in Syria in the early hours of July 4 - Independence Day - but failed to find the hostages and were forced to retreat after a gun battle with the Islamic State (Isis) kidnappers.
Abu Ibrahim al-Raqqawi, a resident of Raqqa, the eastern Syrian city that has become the "capital" of the jihadists' self-declared Islamic State, posted an account of the raid on Facebook.
Raqqawi, who uses a pseudonym for fear of being targeted by Isis, said most of the account was quickly removed by Facebook's administrators.
The mission targeted an Isis stronghold in Uqayrishah, 18km southeast of Raqqa, with tactics similar to those used by US Navy Seals in the capture and killing of Osama bin Laden.
Just after midnight, planes bombed what is believed to be one of Isis's three main headquarters in Syria, a military base named the "Osama bin Laden Camp" by the jihadists.
At the same time, two dozen US special forces landed near a building used by Isis to hold "high value" prisoners. It is believed that the makeshift jail was on the grounds of an oil refinery in the area. The commandos parachuted from Black Hawk helicopters, which had been "specially modified", officials in the US have said.
"The commandos dropped from helicopters which were silent: you couldn't hear their engines or their rotor blades," Raqqawi said.
He reported the account of a friend - a farmer living in Uqayrishah - who said he came face to face with the commandos. The Daily Telegraph cannot independently verify Raqqawi's account, although much of the information he provided correlates with that confirmed in a Pentagon statement on Thursday.
Washington said an American soldier was wounded in the operation and that "several" Isis members died.
Raqqawi's Facebook post said that five Isis fighters were killed, and that two US commandos were wounded.
Once on the ground, the Delta Force operatives apparently blockaded the main road to Raqqa and started to move in on the prison.
They reportedly fought their way to the cells where they thought the hostages were being held, but found no one.
The troops also conducted "house to house" searches of Uqayrishah, Raqqawi said, including in the home of the eyewitness.
Raqqawi reports that the US commandos were assisted by "Jordanian special forces" who were identified by the national flag on their uniforms.
As they were sweeping the houses, Isis "sent backup troops from Raqqa" and a three-hour battle ensued.
"After that, my friend saw that two of the commandos had been shot; one Jordanian and one American," Raqqawi said.
After that, at about 3am, helicopters took the special forces away.
The prison that the US targeted was an area rumoured among residents of Uqayrishah to be the place where Isis kept their "most high value prisoners".
As well as American and British hostages, local residents believed that the 49 Turkish people who were kidnapped from Mosul in Iraq when Isis seized the city in June, were also briefly held there.
However, Raqqawi said that a contact inside Isis had told him that the prisoners had been moved "24 hours before the raid happened".
The attack on the Osama bin Laden Camp caused extensive damage, he said.
Isis had previously boasted about the camp, posting online pictures of its buildings with a banner proudly displaying the name over the door. "The camp used to be very active," said Raqqawi.
"After that, it and the prison were closed for one week.
"They lay silent and there was no movement there."