A US helicopter has crashed in southern Afghanistan, killing all five crew on board, the US military has said.
The Chinook is regularly used as a troop carrier in Afghanistan
The CH-47 Chinook helicopter came down during an operation near Daychopan, in the southern province of Zabul. US ground forces are at the scene.
Afghan officials say the helicopter had dropped off troops and was returning to base when it crashed.
There is no indication of hostile fire, the US military said. An investigation and recovery operations are under way.
A US military statement said the aircraft was "returning from a mission in support of an ongoing operation at the time of the crash".
"There is no indication of enemy involvement in the crash."
Abdul Latif Hakimi, who claims to speak for the Taleban, told the BBC: "We brought the helicopter down with an anti-aircraft rocket."
President Hamid Karzai said he was saddened by the deaths.
A spokesman for the governor of Zabul, Gulab Shah Ali Khil, told the BBC the coalition forces were conducting an operation in the Mara area of Daychopan district.
"This was not a regular operation. They did it because they got some intelligence and went there. The crash took place as they were coming back. It happened between 09:00 to 09:30 this morning."
Several helicopters have crashed in Afghanistan this year, including two US military Chinooks.
In late June, insurgents shot down a Chinook near the Pakistan border, killing all 16 troops on board.
And in April, 15 soldiers and three US civilians were killed when their helicopter got caught up in a sandstorm while returning to Bagram airbase.
In August, 17 Spanish soldiers lost their lives when their Cougar helicopter crashed near Herat in what was believed to be an accident.
There are about 20,000 US-led coalition forces in Afghanistan fighting Taleban and other militants.
More than 1,000 people, most of them suspected insurgents, have died in violence linked to militants this year.
On Sunday, two suspected Taleban fighters were killed and two others wounded in southern Helmand province when the roadside bomb they were trying to plant exploded, officials said.