Afghanistan ? U.S.-led coalition and Afghan security forces killed about 70 suspected militants in Afghanistan, where violence is running at its highest level since the ouster of the Taliban regime six years ago, authorities said Saturday.

The surge in militant attacks comes despite the presence of more than 50,000 foreign troops and 110,000 Afghan police and military officers, as well as a multimillion dollar reconstruction effort to rebuild the shattered nation.

Late Friday, Afghan security forces backed by U.S.-led troops raided compounds in three villages in the remote Pitigal Valley border region, where the coalition said intelligence showed that top militant leaders take refuge as they travel between Pakistan and Afghanistan.

The troops killed more than 20 insurgents and detained 11 others in the raids, which were just 3 miles from the border. They discovered a bomb-making factory and seized weapons and communication gear, the statement said. One coalition soldier was wounded in the raids.