Two car bombs exploded in Baghdad on Monday, killing a bystander and wounding half a dozen others. Gunmen shot down six people, including a child, in a market area of the southern city of Basra, police said. Also Monday, US Secretary of State Condoleezza Rice and British Foreign Secretary Jack Straw urged Iraqi leaders to form a government as soon as possible to curb the bloodshed and rein in sectarian militias behind much of the country's violence. Violence between Shiite and Sunni Muslims has escalated since in February 22 bombing of an important Shiite shrine in Samarra and reprisal attacks against Sunni institutions. In Baghdad's Dora district, four gunmen charged into a Shiite home late Sunday, lined up a brother, two sisters, and an uncle against a wall and shot them dead, police said.