Related: US troops launch major offensive in western Iraq

    BAGHDAD, Oct. 4 (Xinhuanet) -- At least five US service members have been killed in their biggest operation this year in western Iraq launched Tuesday.

    The deaths raised to at least 1,941 the number of U.S. military members who have died since the beginning of the Iraq war in March 2003, according to an Associated Press count.

    The new offensive dubbed River Gate in towns of Haditha, Haqlaniyah and Barwana was designed to uproot insurgents, including al-Qaida fighters who were using the area as a safe haven, the military said.

    "About 2,500 US soldiers and several hundred Iraqi troops were taking part in the operation," the military said in a statement.

    US warplanes and helicopters led the operation aimed at putting down Sunni-led insurgents intensifying their campaign of violence ahead of an Oct. 15 vote on Iraq's new constitution.

    Early on Saturday, around 1,000 US marines launched the Iron Fist offensive in the town of Qaim, near the Syrian border and nearby villages including Se'da, a US statement said.

    According to the military, at least 33 insurgents have been killed in the area since Saturday.

    "Operation Iron Fist began in the early Saturday morning hours with the objectives of rooting out al-Qaida terrorists operating within the area and disrupting insurgent support systems," the statement said.

    Meanwhile, insurgents in Se'da have escalated their attacks against "the local populace and city government officials" during the past several months, the statement said.

    US and Iraqi troops previously launched several offensives against insurgents in towns and villages scattered on the Euphrates River Valley in Anbar province. Enditem

    (Agencies)