Five US service members have died in a helicopter crash in southern Afghanistan.
The cause of the crash has not yet been established, the International Security Assistance Force said.
An ISAF statement said: “The cause of the crash is under investigation, however, initial reporting indicates there was no enemy activity in the area at the time of the incident.”
The crash came on the same day two US troops and five Afghan police and soldiers were killed in a so-called insider attack by a person in an Afghan military uniform in the east of the country.
The new American Defence Secretary Chuck Hagel left Afghanistan earlier on Monday after a difficult first trip to the capital Kabul.
His trip was marred by a suicide bomb attack near where he was holding a meeting, and differences with Afghan President Hamid Karzai, who accused the United States of colluding with the Taliban.
Helicopter crashes are not uncommon in Afghanistan and the Taliban and others often claim to have shot them down, although such claims by insurgents are often exaggerated.
Last August, 11 people, including seven US soldiers, were killed when a Black Hawk helicopter crashed in southern Afghanistan.
The worst such incident was in August 2011, when the Taliban shot down a CH-47 Chinook transport helicopter, killing all 38 people on board, including 25 US special operations troops.