(Updates with death toll) BAGHDAD, Oct 31 (Reuters) - A car bomb ripped through a wedding procession in northeastern Baghdad on Tuesday, killing at least 15 people, including four children, Interior Ministry and police sources said. Another 19 people were wounded when the blast struck a convoy of vehicles celebrating a wedding in the religiously mixed district of Ur. The target of the attack, which one Interior Ministry source said was carried out by a suicide car bomber, was not clear. Sunni Arab Islamist militant groups including al Qaeda use car bombs against civilians in Shi'ite and mixed areas in Iraq under a campaign U.S. and Iraqi officials say is meant to spark a sectarian civil war.