At least six police officers have been killed in a Taliban ambush on their convoy in Afghanistan's northern Balkh province, an official said on Monday.

Abdul Manon Raoufi, operational commander for police in the region, said insurgents attacked the convoy Sunday night in the Dawlat Abad district.

The police were on their way to neighboring Jawzjan province after conducting an anti-insurgent operation in Balkh when the ambush happened, he said.

No group has claimed responsibility. Raoufi said an insurgent leader of the Taliban was also killed in the gunfight.

Separately, in eastern Nangarhar province, two people died and six others were wounded in a bomb explosion Monday, said Hazrat Hussain Mashreqewal, spokesman for the provincial police chief.

The blast targeted police in the Khewa district, but only civilians were killed and wounded, he said.

Taliban fighters have stepped up their attacks against Afghan security forces since 2014, when the international combat mission ended and most foreign troops left the country.