Afghan and U.S.-led coalition troops battled militants and called in airstrikes in a mountainous area of eastern Afghanistan on Sunday, killing several insurgents, while another clash in the south left 15 fighters dead.

The joint U.S.-Afghan force exchanged fire with insurgents during long clashes in the villages of Kendal and Shok in Nuristan province, the coalition said in a statement.

"As the enemy reinforced their positions with additional fighters, the ground force commander called in close air support on the reinforced defensive positions," it said.

"These compounds contained large numbers of heavily armed insurgents who engaged the combined force with a heavy volume of machine-gun fire."

The coalition did not provide an exact estimate of the number of militants killed in the clash.

An unspecified number of insurgents were detained. The troops also "discovered fully loaded weapons and stores of ammunition," the statement said.

In southern Kandahar province, Afghan and NATO troops killed 15 insurgents during clashes Saturday.

The joint forces fought militants in Zhari district of Kandahar province as part of a weeklong operation in the area, a Defense Ministry statement said.

Fifteen insurgents were killed during the fighting, and authorities recovered a number of weapons and ammunition, it said.

On Sunday, Taliban militants ambushed a NATO supply convoy in Andar district of central Ghazni province, sparking a clash that killed two Afghan security guards and two insurgents, said district chief Abdul Rahim Desewal.

Five other guards and two militants were wounded, Desewal said.

NATO supply convoys are usually protected by Afghan guards. Militants regularly attack trucks that haul supplies for the alliance and U.S.-led coalition troops in the country.

Meanwhile, police nabbed a militant leader named Abdul Jabar, described as the deputy of another arrested militant leader, Mansoor Dadullah, the Interior Ministry said in a statement.

Jabar was detained Saturday in Kandahar, Afghanistan's most important southern city and the Taliban's former stronghold, while on his way to Pakistan, the ministry said.

Mansoor Dadullah, the brother of slain Taliban military commander Mullah Dadullah, was detained in February by authorities in Pakistan.

Mansoor Dadullah was dismissed as the movement's top commander in southern Afghanistan by the militia's leader, Mullah Omar, shortly before his arrest.

The Taliban ruled Afghanistan from 1996 to 2001, establishing a harsh regime based on strict interpretation of Islamic law and giving safe haven to Al Qaeda's terrorist leadership until the U.S.-led invasion ousted the group from power.