Baghdad, Iraq ? Seven U.S. Marines were killed in two separate attacks west of Baghdad, where American forces are trying to seal a major border infiltration route for foreign fighters, the military said Tuesday. The deaths pushed the U.S. military death toll in Iraq past 1,800.

One of the Marines died Monday in a suicide car bombing in Hit, 85 miles northwest of Baghdad. The other six were killed Monday in Haditha, 50 miles from Hit – all of them attached to the same suburban Cleveland unit.

“Every single one of them is a hero,” said Lt. Col. Kevin Rush of the Headquarters and Service Co. 3rd Battalion, 25th Marines based in Brook Park, Ohio.

At least 25 American service members have been killed in Iraq in the past 10 days – all but two in combat. The Iraqi Defense Ministry said that since the beginning of April, more than 2,700 Iraqis – about half of them civilians – had been killed in insurgency-related incidents.

Fighting has intensified in recent weeks in Haditha, Hit and other dusty towns along the Euphrates River northwest of Baghdad as American forces step up efforts to seal off the approaches to the Syrian border and prevent foreign fighters from entering the country.

The Marines launched a series of operations in the region in May and June in hopes of pacifying the area so that Iraqi military and civilian forces could assume effective control. But the insurgents have proved resilient.

Covered with white flame-retardant powder, a bomb crater is seen in front of a charred U.S. military Humvee that was the target of a roadside bomb attack in Baghdad, Iraq. The bomb exploded Tuesday at the entrance to a tunnel in central Baghdad. targeting a U.S. military convoy, police said. At least 29 Iraqis were injured in the blast.

The U.S. command said the six Marines were “engaged by terrorists and killed by small-arms fire” in Haditha, which U.S. and Iraqi officials have identified as a major route for insurgents entering Iraq.

After the attack, residents of Haditha said several masked gunmen identifying themselves as members of the Ansar al-Sunnah Army, a major Sunni Arab insurgent group, appeared in the market carrying helmets, flak jackets and automatic rifles they said belonged to U.S. troops.

They distributed fliers claiming they had killed 10 American service members.

“They were on a mountain near the town so we went up, surrounded them and asked them to surrender,” the statement said. “They did not surrender so we killed them.”

A similar claim in the name of Ansar al-Sunnah was posted on an Islamic Web site.

In Baghdad, a roadside bomb exploded at the entrance to a highway tunnel in central Baghdad as a U.S. military convoy was passing, damaging two Humvees. At least 29 Iraqis were wounded, officials said. But there was no report of any American casualties.

At least 1,801 members of the U.S. military have died since the beginning of the Iraq war in March 2003, according to an Associated Press count. At least 1,382 died as a result of hostile action. The figures include five military civilians.

The toll among Iraqis, however, has been much higher.

On Tuesday, the Defense Ministry said that since April 1, a total of 2,709 Iraqis have died in violent attacks, including 1,413 civilians. The rest were soldiers, police and insurgents.

The death toll for July was 656, the ministry said. That was the second deadliest month since the Shiite-dominated government was installed – surpassed only by May’s figure of 967 deaths.

However, records-keeping in Iraq is irregular, especially in areas where the insurgents are strong, and the real figure is probably higher.