Two days after a U.S. Marine was killed in an ISIS rocket attack at a new firebase in northern Iraq, the base came under attack again Monday, a U.S. military spokesman told reporters.

No Americans were killed or wounded in the latest attack, according to Col. Steve Warren, a U.S. military spokesman based in Baghdad.  

A “squad-sized” element of ISIS fighters, likely under 10, crept in close enough to attack the U.S. base, known as Firebase Bell, using small-arms fire. Two of the fighters were killed and the others ran off, the spokesman added.  

Warren says he believes the U.S. Marines were specifically targeted in the rocket attack over the weekend and thinks further attacks are likely.

“We're in a dangerous place, and there's a war going on. So, we have to expect that there will be attacks,” he said.

Despite President Obama’s pledge of “no boots on the ground” against ISIS, some U.S. lawmakers say it’s been unclear where the advising mission ends and combat begins.

In addition, a militia backed by Iran warned it would “deal with” U.S. Marines fighting ISIS in Iraq as “forces of occupation.” In an announcement on its TV channel al-Ahd, the militia added, “The forces of occupation are making a new suspicious attempt to restore their presence in the country under the pretext of fighting their own creation,” referring to ISIS.

 

 

Warren said Katyusha rockets were used in the ISIS attack Saturday. Some of the wounded Marines have been transferred to a U.S. military hospital in Germany.  

That attack killed Marine Staff Sgt. Louis F. Cardin of Temecula, Calif.

Cardin was assigned to the 2nd Battalion, 6th Marine Regiment, 26th Marine Expeditionary Unit, Camp Lejeune, North Carolina, the Pentagon said. His body was returned to Dover Air Force base Monday afternoon.

In the past two weeks, the Pentagon sent a company of U.S. Marines from the 26th Marine Expeditionary Unit aboard the USS Kearsarge and other amphibious ships to Iraq. A defense official later told Fox News the number of Marines at the new firebase is close to 180.

“They're there to provide force protection,” Warren said when asked about the mission. He said the new base is similar to two other Iraqi bases where U.S. forces are supporting the training of the Iraqi military.

Warren said the Marines have set up four 155mm howitzer weapons to protect nearly 100 US advisors and thousands of Iraqi army troops in Makhmur, located nearly 75 miles southeast of the ISIS stronghold of Mosul.

Warren described the new American base as located a “few hundred meters” away from a neighboring Iraqi base, but admitted there are no Iraqi forces with the U.S. Marines.

“This is the first time we've established a spot that's only American,” Warren said.

There are nearly 3,800 American troops on the ground in Iraq, a spokesman for the US-led coalition said earlier Monday.

Col. Warren said it was U.S. military policy not to reveal the exact numbers of U.S. military personnel inside Iraq.

The Iraqi military is planning an assault on Mosul in the coming months, but  many senior U.S. military leaders have voiced skepticism of late that Mosul will be retaken in the coming year.

Elsewhere, Warren said the U.S.-led coalition destroyed nine weapons facilities in western Iraq in the city of Hit last week.  Warren said “chemical infrastructure,” was probably destroyed but could not be certain.

Lucas Tomlinson is the Pentagon and State Department producer for Fox News Channel. You can follow him on Twitter: @LucasFoxNews