BASRA, Iraq (Reuters) -A car bomb exploded outside a building housing members of a Shi”ite militia associated with the Iraqi government on Sunday, killing a child, police and witnesses said.

The early morning blast also wounded six people in the southern city of Basra, a hospital source said.

The explosion left a large crater and damaged a building housing members of the Badr movement, which is linked to one of the main Shi”ite parties in the U.S.-backed-government.

The attack came as tensions rise among rival Shi”ite groups and political parties from across Iraq”s volatile sectarian divide as they jockey for position ahead of December elections.

The Iranian-trained Badr movement recently clashed with militiamen loyal to nationalist Shi”ite cleric Moqtada al-Sadr in several cities.

Sunni Arabs once dominant under Saddam Hussein have accused the Badr movement of operating government-sanctioned hit squads against Sunnis, a charge denied by both Badr and the government.

Basra, Iraq”s second city, has been hit by several recent bombings after enjoying relative calm compared to central Iraq, where Sunni insurgents are waging a campaign of suicide bombings and shootings aimed at bringing down the government.