BAGHDAD // Two policemen were shot dead and their bodies set ablaze at a Baghdad checkpoint today while two of their colleagues and an anti-al Qa'eda fighter were also killed, an interior ministry official said. Insurgents shot the two policemen as they sat in their car in eastern Baghdad, the official said, and then set it on fire, while two others were killed by silenced pistols at a checkpoint in the west of the Iraqi capital. Today's incident was the third time in two weeks that members of the security forces' bodies have been burned after being killed by insurgents. In Al Shaab district northeast of Baghdad meanwhile, a member of the government-backed Sahwa (Awakening) militia was shot dead at a checkpoint, the official said, and two other fighters wounded. The Sahwa, known in the US military as the "Sons of Iraq" sided with the US against al Qa'eda from late 2006, helping turn the tide of Iraq's brutal insurgency. Dozens of the former Sunni rebels have been killed in apparent revenge attacks in recent months.