A helicopter crash in Maidan Wardak province of Afghanistan killed 31 American Special Force troops.
Also on board the chopper, a Chinook, were seven members of the Afghan Forces who too were all killed in the crash.
The crash late Friday represents the biggest death toll in a single incident for international forces in Afghanistan since the start of the war in 2001
Even as the US and afghan governments claim that the NATO Chinook had crashed, the Taliban were quick to claim that the helicopter had been shot down.
Chinooks are used for transporting larger numbers of troops and supplies around in the warzone of Afghanistan. There are currently around 140,000 foreign troops in Afghanistan, around 100,000 of them from the United States, fighting as part of the international force that has been in the country for almost 10 years.
Some troop withdrawals have already begun as part of a process which is due to see all foreign combat forces leave the country by the end of 2014.