Afghan officials say at least 12 policemen have been killed or wounded in two separate Taliban attacks on checkpoints.

Authorities said six policemen were killed in an early morning gunfight Wednesday with insurgents in the Qarabagh district 120 kilometers southwest of Kabul.

On Sunday, three police were killed in a similar insurgent attack on their checkpoint in the same district.

In the second incident Wednesday, at least six policemen were killed or wounded when a suicide bomber blew himself up at a checkpoint in Afghanistan's eastern Ghazni province. Clashes erupted between insurgents and police after the bombing.

In other violence, NATO said one of its soldiers was killed Wednesday in an insurgent attack in southern Afghanistan. It did not release the name or nationality of the soldier.

The Taliban has stepped up its attacks on government officials and Afghan and international troops in recent months.