Three foreign troops were killed in Afghanistan on Sunday, including two who died when their helicopter crashed in the east, the NATO-led International Security Assistance Force (ISAF) said.
ISAF added that the cause of the crash was being investigated but there were no signs of enemy fire in the area at the time.
The Taliban, the key militant group behind the near 10-year long insurgency, claimed credit for bringing down the helicopter, although the group is known regularly to exaggerate its claims.
Its spokesman Zabihullah Mujahid said it came down in Khost province, which borders Pakistan. Afghan media, citing eyewitnesses, also said the helicopter crashed in Khost.
In line with policy, ISAF did not give further details of the incident or reveal which country the dead troops came from.
Meanwhile in southern Afghanistan, another soldier was killed "following an insurgent attack", ISAF said.
The deaths in the south and east, which feature some of the worst battlegrounds in the Afghan war, came as US Defense Secretary Robert Gates visited Afghanistan to say farewell to troops before leaving his job this month.
There are around 130,000 US-led international troops in Afghanistan fighting a Taliban-led insurgency which has lasted for nearly 10 years since a 2001 invasion brought down their Islamist regime in Kabul.
The latest casualties brought the foreign military death toll to at least 228 so far this year, according to independent website iCasualties.org.