Iraqi officials say a rare car bomb in the Shiite holy city of Karbala has killed seven civilians and wounded nearly two dozen.

A police officer says the bomb went off in a commercial area in the city, which is some 90 kilometers (55 miles) south of Baghdad. Karbala is home to the Imam Hussein Shrine, one of the holiest sites in Shiite Islam.

A medical official confirmed the casualty figures. Both officials spoke on condition of anonymity because they were not authorized to brief reporters.

No one immediately claimed responsibility for the attack.

The Islamic State, a Sunni extremist group, often targets Iraq's Shiite majority. Baghdad has seen a string of near-daily attacks in recent weeks, but mainly Shiite southern Iraq has largely been spared from the violence.