The Afghan Defense Ministry says Afghan and U.S-led forces inflicted heavy casualties on insurgents in a battle Sunday in the eastern province of Nuristan.

Neither Afghan nor U.S. military officials said how many insurgents were killed. Afghan officials said one of their soldiers had been killed.

The military officials said there were no reports of civilian casualties.

Nuristan officials dispute that, saying at least 20 civilians died in the attack and more were wounded.

Defense Ministry officials say eight insurgents were captured, while Nuristan leaders say those detained were civilians.

The Afghan Defense Ministry is investigating the situation.

Afghan and U.S. forces undertook the operation to clear insurgents from the remote province near the Pakistani border. Nuristan is a known stronghold of Taliban-led militants.

One Nuristan leader said the Taliban had been in the area, but left before the fighting started.

Some information for this report was provided by AFP and Reuters.