Updated

Five U.S. troops in southern Afghanistan have been killed by a roadside bomb, a Pentagon official told Reuters Thursday.

Earlier, NATO said five foreign troops were killed, but declined to give identities.

Yesterday, international forces killed the Taliban insurgents responsible for shooting down a U.S. helicopter and killing 38 U.S. and Afghan forces over the weekend, but they are still seeking the top insurgent leader they were going after in Saturday's mission, the top American commander in Afghanistan said.

Marine Corps Gen. John Allen told a Pentagon news conference that an F-16 airstrike Monday took out fewer than 10 insurgents involved in the attack on the Chinook helicopter.

In a separate statement Wednesday, the military said the Monday strike killed Taliban leader Mullah Mohibullah and the insurgent who fired the rocket-propelled grenade at the helicopter.

The military said intelligence gained on the ground provided a high degree of confidence that the insurgent who fired the grenade was the person killed. It did not provide further details.

The Associated Press contributed to this report.