BAGHDAD, Oct. 21 (Xinhuanet) -- Three US Marines were killed by a roadside bomb west of Baghdad and a fourth US soldier was killed in a separate attack northwest of the capital, the US military said on Friday.

    The three Marines were patrolling west of Baghdad when their vehicle was hit by an improvised roadside bomb, said the US military, adding that US troops then killed two insurgents and detained four others suspected of involvement in the attack.

    Another US soldier died of wounds sustained in "an indirect fire attack" in Hit, northwest of Baghdad, the military said.

    The latest deaths bring the number of US soldiers who died in Iraq to 1,992 since the US-led invasion of the country in March 2003. Enditem