Four US soldiers have been killed after an explosion hit their vehicle in eastern Baghdad, bringing the number of Americans killed in action since the invasion to 600.
Five soldiers were wounded in today's attack. Flames and smoke engulfed the wreckage of a Humvee vehicle as other US troops cordoned off the scene and evacuated the wounded, Reuters reporters at the scene said.
"Four US soldiers were killed and five wounded by an explosion near their vehicle in eastern Baghdad," said a US military spokesman. "The cause of the explosion is still under investigation."
Local witnesses said militants had fired a rocket-propelled grenade at the vehicle as it drove along a dual carriageway surrounded by open ground in eastern Baghdad.
Roadside bombs are also often used to inflict casualties on US troops travelling in convoys in the country.