BAGHDAD, Iraq — U.S. and Iraqi forces in the western province of Anbar have seized thousands of pounds of explosives and arrested dozens of suspected insurgents in a three-day sweep, military officials said yesterday.

The thrust by about 1,000 U.S. Marines, soldiers and sailors and 100 Iraqi troops, called Operation Sword, centered on towns along the Euphrates River about 90 miles west of Baghdad.

Marine spokesmen have said the operation, like other recent sweeps farther west, is aimed at driving insurgents out of towns and disrupting their ability to move guerrillas, weapons and supplies from neighboring Syria into western Iraq and other parts of the country.

The Iraqi Red Crescent Society says 6,000 families have been displaced across Anbar province in the fighting and are suffering in the summer heat.

Iraqi army Capt. Hussein Abbas said about 2 tons of explosives had been confiscated in Hit and that 45 suspects had been arrested, including people from Saudi Arabia, Jordan and Syria.

In Baghdad yesterday, the U.S. military's chief spokesman in Iraq, Air Force Brig.

Gen. Donald Alston, told reporters the military estimated that foreigners accounted for roughly 5 percent of an insurgency believed to number between 15,000 and 20,000.

The insurgents — Iraqis and foreigners alike — are overwhelmingly Sunni Muslim Arabs. Iraqi leaders have repeatedly emphasized the importance of undercutting the violence by drawing Iraqi Sunnis into a political process that is so far dominated by Shiite Muslims and ethnic Kurds.

At least 68 U.S. soldiers, Marines and sailors were killed by hostile fire in Iraq during June, the highest since November 2004, when 125 U.S. troops were killed by hostile fire, many during intense combat in the Anbar province city of Fallujah.

U.S. deaths in Iraq increased about 34 percent in the past 12 months compared with the year earlier. About 882 U.S. troops were killed in the past 12 months compared with 657 in the year prior. In total, 1,743 U.S. troops have died in the war, according to an Associated Press count.

At least 39 of the June deaths came in Anbar. And there were disturbing signs that the insurgency is active again in Fallujah, which American forces retook from insurgents in November.

But on June 23, six Marines and sailors were killed in Fallujah after a suicide bomber slammed his car into their convoy.

Compiled from The Washington Post, Knight Ridder Newspapers, USA Today, The Associated Press and Los Angeles Times.