A suicide bomber has attacked a memorial for an assassinated police commander, killing four police officers in eastern Afghanistan.

Authorities say the bomber was targeting the police chief of Kunduz province, Samiullah Qatra, when he entered the mosque Friday in Kunduz city, where a remembrance ceremony was being held.

Security forces confronted the bomber, who then detonated his explosives. Officials say Qatra was unhurt, but four people were killed and 18 others were wounded in the blast.

Qatra's predecessor was killed by a suicide bomber in March.

The police officers were attending a memorial service for regional police commander General Dawood Dawood, who died last month in a suicide bombing in northern Takhar province. The Taliban said it was behind the May 28 attack on the governor's compound, which also killed six provincial officials and NATO soldiers.

No one claimed responsibility for Friday's attack in Kunduz. Local officials blamed the Taliban, who have stepped up attacks on Afghan officials and security forces during the militant group's spring offensive.