KABUL: Two helicopter crashes in Afghanistan killed 11 US soldiers and three US civilians on Monday, NATO-led forces said in a statement.
Neither crash was caused by hostile fire, NATO said.
This year has seen a surge of violence in Afghanistan as an increasingly fierce Taliban step up operations against US and NATO forces operating in the country.
Seven US service members and three US civilians were killed when a NATO helicopter crashed in western Afghanistan following an operation against insurgents in which a dozen Taliban fighters were killed.
Eleven US troops, 14 Afghan soldiers and a US civilian were injured in the crash.
Four US service members were killed and two were injured when two helicopters operated by NATO-led troops collided in mid-air in southern Afghanistan, NATO said in an earlier statement.
On Saturday in eastern Afghanistan, one US soldier was killed in a roadside bomb attack and another died of wounds from an insurgent attack, NATO said in a statement on Monday.
A spokeswoman for ISAF, the International Security Assistance Force, could not give any further information on the casualties or the exact location of the crashes.