A leading Sunni cleric called for religious and ethnic groups to take a stand against violence as Iraq endured a third consecutive day of sectarian killings - the worst, a suicide car bombing at a Shiite mosque that killed at least 12 worshippers.

A suicide car bomber struck worshippers leaving a Shiite mosque in Tuz Khormato in northern Iraq today, killing at least 10 people and wounding 21 others.