The Islamic State is increasingly targeting civilian residents and murdering hundreds each week in the embattled city of Mosul, a top U.S. general in Iraq said Wednesday.

The civilian attacks are proof that the group is losing the fight in western Mosul, where U.S. forces are helping Iraqi security forces and Kurdish groups in a months-long effort to liberate the city, according to Army Maj. Gen. Joseph Martin, commander of the Combined Joint Forces Land Component Command of Operation Inherent Resolve.

Civilian attacks are being waged with vehicle bombs and improvised explosive devices, and the Islamic State has lobbed 7,000 mortars and rockets indiscriminately into the liberated eastern section of the city, said Martin, who spoke to Pentagon reporters from Iraq.

"The number of civilians murdered by ISIS on a weekly basis is in the hundreds with evidence showing that's increasing," he said.

U.S. coalition forces have fought in the city for six months and have managed to retake much of Mosul, which was seized by the Islamic State in 2014 when it pushed over the Syria border into Iraq.

"As they become more desperate, their tactics become more desperate and their inhumanity increases," Martin said. "What we are seeing in western Mosul is the continued exploitation and the expanding exploitation of the human element within the city."

The loss of Mosul would be a major strategic defeat for the Islamic State and sever its center of power in Iraq, leaving its defacto capital of Raqqa, Syria, as the central remaining target of coalition forces.

Over the weekend, the group waged a chemical attack on Iraqi security forces that were reportedly accompanied by U.S. and Australian advisors — the second such attack in Mosul in recent days.

Martin said neither U.S. nor allied personnel were injured in the attack and that it had not been confirmed whether the chemical substance was a mustard agent.