Iraqi police officials say a suicide bomber killed 17 people at a Baghdad memorial service for a Shiite militia fighter killed in battle against the Islamic State group.

The official says the bomber detonated his explosives' vest on Friday at the service in the southwestern Baghdad suburb of Hay al-Amal. At least 43 people were wounded.

No one has claimed responsibility for the attack but the Islamic State militant group has frequently targeted large Shiite gatherings. The radical Sunni group believes that Shiites are apostates who have strayed from Islam.

Also in Baghdad, police say a roadside bomb detonated at a Shiite shrine in Sadr City, killing at least five people and wounding 15.

All officials spoke on condition of anonymity as they are not authorized to talk to reporters.