KABUL -- Militants attacked a provincial government building in eastern Afghanistan on Sunday, killing at least nine people, officials said.

Attahullah Khogyani, the spokesman for the governor of Nangarhar province, said a suicide car bomb exploded outside the building, which belongs to the provincial finance directorate. The attackers then stormed the building, trading fire with security officials.

He said security forces killed one of the attackers and surrounded the building, adding that he gunbattle was still underway.

Inamullah Miakhial, spokesman for the Nangarhar hospital, said nine people were killed and more than 35 wounded.

No one immediately claimed responsibility for the attack. Both the Taliban and a local Islamic State affiliate have carried out numerous attacks in Nangarhar.

Afghan security forces have struggled to combat the Taliban and IS since the U.S. and NATO formally concluded their combat role in the country in 2014, shifting to a support and counterterrorism mission. The Taliban have seized control of districts across the country, and the two groups have carried out attacks in the Afghan capital, Kabul, in recent months that killed scores of people.