Iraqi officials say a suicide car bomb attack has killed eight Iranian pilgrims and wounded 25 others north of Baghdad.

Police said that in the Friday morning attack, a suicide bomber rammed his explosive-laden car into a bus carrying Iranian Shiite pilgrims who were on their way to visit holy shrines in the city of Najaf.

The attack took place near the town of Muqdadiyah, about 90 kilometers (60 miles) north of Baghdad.

A medical official confirmed the causality figures. All officials spoke on condition of anonymity because they were not authorized to talk to reporters.

Violence has spiked in Iraq in recent weeks. Shiite pilgrims are often targeted by Sunni extremists who claim they are not true Muslims.