AS military officials recovered wreckage from the scene of a helicopter crash in Afghanistan that killed 30 troops, including 22 Navy SEALS, further details emerged on the deadliest single incident to hit US forces since the war began a decade ago.
The troops, aboard a US Army Chinook transport helicopter, had been on a mission to help a unit of Army Rangers that was pinned down by enemy fire in Wardak province of eastern Afghanistan during an operation to target a Taliban commander, military officials told CNN.
All were killed when the craft was apparently hit by insurgent fire as it was leaving.
The Taliban has claimed it shot down the chopper, losing eight of its own fighters in combat, but US and NATO officials have not yet provided a full picture of events.
A senior US administration official in Washington said the craft was apparently attacked by insurgents. NATO confirmed the overnight crash took place and that there "was enemy activity in the area."
"We are in the process of accessing the facts," said US Air Force Capt. Justin Brockhoff, a NATO spokesman, according to FOX News Channel.
Two Afghan government officials told The Wall Street Journal that a lone militant using a rocket-propelled grenade shot down the chopper as it was taking off after the night-time mission in Tangi Valley.
The attack killed 22 members of the US Navy SEALs Team 6, five American helicopter crew members and three air force special controllers, along with one civilian interpreter and seven Afghan commandos.
A senior US military official told FOX that all bodies had been recovered from the site, but recovery of helicopter was still ongoing.
The NATO-led International Security Assistance Force (ISAF) announced an immediate probe into the crash.
The incident is a major blow to US special forces and comes just months after members of the close-knit, elite Team 6 stormed Usama bin Laden's Pakistan compound and shot dead the terror chief in May.
None of those killed in the chopper crash were believed to have taken part in the Pakistan raid on the al-Qaeda leader's hideout.
An unnamed naval special warfare source told the Navy Times: "There's no precedent for this. It's the worst day in our history by a mile."
US Lieutenant General John Allen, commander of the ISAF mission, said: "No words describe the sorrow we feel in the wake of this tragic loss. All of those killed in this operation were true heroes."
President Barack Obama echoed his remarks in a statement Saturday.
"Their deaths are a reminder of the extraordinary sacrifices made by the men and women of our military and their families, including all who have served in Afghanistan," he said.
Mr Obama received a call from his Afghan counterpart, Hamid Karzai, who "reiterated his condolences" for the loss of American servicemembers, according to White House statement.
"The two Presidents reaffirmed their commitment to the mission in Afghanistan, which is critical to the security of both our countries, and agreed to stay in close contact," the statement said.
In other violence, four NATO service members were killed yesterday in two separate insurgent attacks in Afghanistan, according to AFP.
There are currently approximately 100,000 US troops in Afghanistan who are joined by 40,000 soldiers from other countries as part of the campaign against the Taliban insurgency.
Obama has announced plans for a gradual drawdown of US troops in Afghanistan, with all foreign troops expected to be out of the country by 2014 as Afghan forces prepare to take charge of their own security.