Abu Musab al-Zarqawi claimed responsibility last night for the killing of
50 unarmed Iraqi army recruits in one of the bloodiest attacks on the country's fledgling security forces.
Guerrillas also killed a US diplomat in a mortar attack on a US military headquarters on the edge of Baghdad airport in the first known killing of an American diplomat in Iraq since last year's US-led invasion.
Zarqawi's newly renamed group, the Al Qaeda Organisation for Holy War in Iraq, said in a statement posted on a website often used by militants that it killed 48 "apostates" in the attack. Other reports said 50 died.
"The mujahideen killed them all, stole two vehicles and the salaries they had just received from their masters," said the statement. Its authenticity could not be verified.
The attack was another blow to the US-backed interim government's efforts to build up Iraqi security forces to tackle a raging insurgency along with US-led forces before national assembly elections scheduled for January.
Speaking on al-Sharqiya Television, monitored by the BBC, Iraqi Defence Minister Hazim al-Shaalan said those who killed the army recruits would face the maximum punishment.
"Of course, once we identify and arrest the perpetrators, we will take tough measures against them. God willing, when we arrest them, they will receive capital punishment," he said.
Zarqawi's group has claimed responsibility for scores of suicide bombings that have killed hundreds and it has also beheaded foreign hostages.