BAGHDAD, June 18 (Xinhuanet) -- US marines launched a second large-scale operation in western Iraq on Saturday, intensifying efforts to wipe out insurgents and foreign fighters in the Euphrates valley near the Syrian border.

    Some 1,000 US marines backed by helicopters launched Operation Dagger east of Tharthar lake, just one day after US and Iraqi troops began Operation Spear in Qaim town, also near the Syrian border, killing 50 insurgents, the US military said.

    US forces believe foreign fighters often infiltrate into Iraq through its porous border with Syria.

    The US troops carried out two major offensives in the area last month, killing 125 insurgents in the first offensive, named Operation Matador, and leaving 14 dead in the second named Operation New Market. Enditem