Four US soldiers die in Afghanistan chopper crash: NATO

Three NATO helicopters crashed in Afghanistan today, two apparently colliding mid-air killing four US soldiers and another following a deadly raid on suspected drug traffickers, the military said.

Two other soldiers were injured in what the NATO-run International Security Assistance Force (ISAF) said was believed to have been a mid-air collision in the south, a Taliban heartland and the most volatile part of Afghanistan.

"Four ISAF service members were killed and two others injured in the incident," it said in a statement. "The incident is currently being investigated, but it is confirmed that hostile fire was not involved," it said.

The current year has been the most deadly for the more than 100,000 NATO and US troops fighting a resurgent Taliban since the 2001 US-led invasion ousted the Islamists' extremist regime in Kabul.

The independent icasualties.org website, which keeps a running tally of foreign troops deaths in Afghanistan says that so far in 2009, 424 have died. Of those, 256 were American, icasualties says.

Colonel Wayne Shanks, US military spokesman in Kabul, confirmed the four dead soldiers were Americans. Another helicopter came down in western Afghanistan -- also in the early hours of Monday, an ISAF spokesman said. "Military casualties are reported and a recovery operation is underway," the statement said.