Six U.S. Soldiers Reported Killed In Afghan Crash : The Two-Way It isn't yet known what caused the aircraft, said to be a helicopter, to come down. But Reuters reports that initial reports do not indicate that it came under attack. Regardless, it is the deadliest incident involving foreign troops in months.

Six U.S. Soldiers Reported Killed In Afghan Crash

The crash of a military aircraft Tuesday in Afghanistan killed six members of the International Security Assistance Force who were on board, military officials say, and NPR's Tom Bowman has been told by military sources in a position to know that all six were Americans.

Fox News and several other outlets are also reporting they've been told the casualties were Americans.

According to Reuters, the crash happened in southern Afghanistan and "did not appear, initially at least, to be the result of insurgent attack."

But, as the wire service also notes, "it was the most deadly incident for foreign soldiers in Afghanistan in months."

Fox News quotes a deputy governor of Zabul province, Mohammad Jan Rasoolyar, as saying the aircraft was a helicopter.

We'll update as more information comes in.

Update at 11:10 a.m. ET. Second Helicopter Crash This Year:

NPR's Bowman tells our Newscast Desk that "Pentagon officials say there were no reports of enemy activity in the area at the time of the crash." Also, Tom says, "this is the second deadly helicopter crash so far this year involving U.S. forces in Afghanistan. In April, four were killed in a helicopter crash outside Kandahar. In that crash there was no evidence of enemy fire."

In 2013, there have been 125 American fatalities in Afghanistan.