A Marine artillery unit in northern Iraq has continued to come under sporadic attack while supporting Iraqi troops since Staff Sgt. Louis F. Cardin was killed eight and others were wounded on March 19 by ISIS rocket fire, a top coalition commander said Thursday.

"There's still the occasional indirect fire attack" aimed at the base, where Marines from the 26th Marine Expeditionary set up four 155mm howitzers earlier this month, said British Army Maj. Gen. Doug Chalmers.

However, "Attacks on the (Marine) base since we sadly lost Staff Sgt. Cardin have sort of dropped down," Chalmers said, as Islamic State of Iraq and Syria fighters focus more on Iraqi Security Forces (ISF) troops who have been attempting to push north toward Mosul from positions near the town of Makhmour, about 60 miles southeast of Mosul.

The presence of about 200 Marines at Makhmour was disclosed by the Pentagon only after the death of Cardin, 27, of Temecula, California.

The base had been called Fire Base Bell but was recently renamed to Kara Soar Counter Fire Complex to make clear it's conducting defensive operations, CNN reported.

Chalmers, a deputy commander for strategy and sustainment in Combined Joint Task Force-Operation Inherent Resolve, acknowledged that there have been varying reports on the success of the Iraqi efforts to move towards Mosul from Makhmour.

Western reporters in Makhmour, which has been billed by the Iraqi Security Forces as a staging area for the offensive to retake Mosul, said that Iraqi troops abandoned positions after coming under attack from ISIS but Chalmers said they were making progress.

"The battle ebbs and flows," he said. "There are some areas that are tougher and take a bit longer, but "I'm pretty confident they're advancing along the line of their objectives."

On Wednesday, Iraqi Defense Minister Khaled al-Obeidi toured Makhmour and admitted that the planned advance to the north had stalled.

"Yes, that's right, at the beginning the operation was slow and that was because we were not familiar with the area. We want to start the operation slowly to see what kind of tactics [the enemy] use against us," al-Obeidi told Rudaw, the Kurdish news outlet.

Chalmers said that the Marines at the base have been firing their 155mm howitzers in response to ISIS rocket fire and also in support of advancing Iraqi troops.

Chalmers, who arrived in Iraq about six months ago with Army III Corps headquarters staff from Fort Hood in Texas, said no decisions have been made yet on whether the Marines and the 155s would move forward with the Iraqi Security Forces when they begin to advance toward Mosul.

-- Richard Sisk can be reached at Richard.Sisk@Military.com.