Officials: NATO clashes with Pakistani troops

Tensions mounted Tuesday when NATO helicopters flying in eastern Afghanistan fired across the border into Pakistan after being fired on twice, according to a NATO official.

NATO's International Security Assistance Force later received reports that two Pakistani soldiers were wounded.

Two coalition helicopters supporting operations at U.S. Forward Operating Base Tillman in Afghanistan were fired upon from the Pakistani side of the border, said the NATO official, who did not want to be identified because the information has not yet been released publicly. After being fired upon a second time, the helicopters returned fire, the official said.