The Pave Hawk helicopter is a mainstay of the US special forces
The remains of six US servicemen killed in a helicopter crash in south-eastern Afghanistan have been sent home.
They died when their HH-60 Pave Hawk helicopter crashed near the town of Ghazni while on a mission to rescue two Afghan children.
Officials say the helicopter was not shot down by hostile forces.
It is the second time this year a US helicopter has crashed in Afghanistan.
In a sombre ceremony at the Bagram air base near Kabul, metal caskets draped in the US flag and containing the bodies of the dead crew were loaded onto a C-17 transport plane.
The caskets will be flown to Landsthul, Germany before being sent on to the United States.
US army spokesman Colonel Roger King praised the sacrifice made by the six men.
"You've got military personnel who are conducting a flight that's basically a humanitarian mission," Colonel King said, the Associated Press news agency reports.
"They're trying to go out and save some Afghan kid's life - it's wrenching."
The helicopter crashed at about 1620 GMT, on Sunday about 18 miles (29 kilometres) from Ghazni, south-west of Kabul.
The names of the victims were being held back until relatives were informed.
Colonel King said an investigation would try to determine if bad weather had been a factor.
The US says the HH-60 Pave Hawk was on a "medical evacuation mission" and that it was not taking part in a large-scale operation, Valiant Strike, against remnants of the Taleban and al-Qaeda organisations.
The last US helicopter crash in Afghanistan was on 30 January, when an army helicopter came down near Bagram air base, killing all four crew members.
Pave Hawk is the standard special forces adaptation of the Black Hawk.
Flown by the Air Force Special Operations Command, the Pave Hawk's primary roles are infiltration, recovery and re-supply of special forces units operating behind enemy lines, day or night.
The helicopters are fitted with all-weather radar, which enables them to operate in poor conditions.
Pave Hawks saw service during Operation Desert Storm in Iraq in 1991, recovering downed coalition pilots in Iraq, Saudi Arabia, Kuwait and the Persian Gulf.