US fighter planes killed 40 people identified by military authorities as "insurgents" in Iraq last night after launching air strikes on a makeshift barricade set up on a road near the Syrian border.

US fighter planes killed 40 people identified by military authorities as "insurgents" in Iraq last night after launching air strikes on a makeshift barricade set up on a road near the Syrian border.

Seven precision-guided missiles were fired at heavily armed militants who were stopping and searching civilian cars at gunpoint near Karabilah, close to Qaim, US Marines said.

A spokesman said that the insurgents - who were all killed - were armed with AK-47 assault rifles, machine guns and rocket-propelled grenade launchers. "There are no reports of civilian casualties or collateral damage," he added. The region is known as a haven for Islamic extremists passing between Iraq and Syria to attack US and Iraqi security targets.

The latest raid follows two major US offensives in the area last month that killed an estimated 140 militants. Seven marines have died in Iraq's unstable Anbar province since Thursday, and the bodies of 21 dead Iraqi men - a number of them beheaded and most of them shot execution style - were found on Friday in three separate locations near Qaim. It is feared the bodies may be those of 20 Iraqi soldiers who went missing on Wednesday after leaving a military base bound for a break in Baghdad.

Elsewhere in Iraq, at least 35 people died in the latest spate of suicide bombings and gun attacks yesterday. The most startling incident was when a suicide bomber dressed as a policeman blew himself up during a morning roll call at the heavily guarded Baghdad headquarters of the Wolf Brigade commando unit, killing at least three people, officials said. Eyewitnesses reported at least five died.

Another suicide car bomber later blew himself up in front of the Slovakian embassy, wounding four people.

Just south of Baghdad, gunmen killed at least 11 Iraqi construction workers and wounded another three when they riddled their minibus with bullets as it drove in the so-called Triangle of Death, police said. The attack occurred in Diyara, 30 miles south of Baghdad, and the men worked on construction projects in Iraq and American bases, police added.

Two US marines were killed on Friday in a roadside bomb attack west of Fallujah. At least 1,693 US military personnel have died since the war began in March 2003.

In Baghdad, gunmen in a speeding car attacked another Interior Ministry commando convoy in western Baghdad's Mansour area, killing three, police said.

The attack at the two-storey headquarters of the Wolf Brigade follows weeks of accusations against the Shia Muslim-dominated force by Sunni leaders, who accuse it of kidnapping and killing Sunnis, including clerics. The Interior Minister, Bayan Jabr, said the attacker was a former Wolf Brigade member who was targeting the commando force's commander, Brigadier Mohammed al-Quraishi.

Also yesterday: two Oil Ministry employees were found shot dead in Baghdad's southern Dora district. The bodies were found in a canal under a footbridge and one of the men was handcuffed and wearing civilian clothes.