MOSUL — (CNN) US troops operating around Mosul have come under fire from ISIS and some have been wounded in the last six to eight weeks as they have moved closer to the front lines in Iraq, military officials acknowledged Tuesday.

“Yes, they have been under fire at different times,” Col. John Dorrian, a coalition spokesman for Operation Inherent Resolve said at a Pentagon news conference.

A US defense official later told CNN that some number of troops had been wounded and medevaced off the battlefield but declined to say how many have been wounded.

The US forces in the area are providing advice and assistance to Iraqi units battling to retake Mosul. One of their key tasks is to help Iraqi units targeting ISIS strongholds.

Dorrian declined to offer specifics on the firefights that have taken place, but said: “They have come under fire at different times. They have returned fire at different times in and around Mosul. That has happened at different times.”

The coalition posted several photos on its Twitter and Facebook accounts showing US troops in and around Mosul helping with calling in airstrikes and artillery. The captions in those official photos specifically mention assisting the Iraqis trying to liberate western Mosul, which is seen as a very tough fight because ISIS is well dug in.

Dorrian also reiterated a long-held view inside the uniformed services that although US troops try to avoid being involved in firefights, when they are confronted they defend themselves in a full combat mode.

“When someone is shooting at you, that is combat,” Dorrian said. “Yes, that has happened.”

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