An Iraqi government spokesman says Iraqi forces are making progress in the military operation to retake the western city of Ramadi from the Islamic State group.

The operation was launched in earnest in November.

Spokesman Sabah al-Numan says the troops on Tuesday crossed the Euphrates River to reach downtown Ramadi. The city has been under ISIS control since May, when Iraqi forces withdrew under an ISIS onslaught.

Al-Numan says sporadic clashes are underway and that Iraqi forces are being forced to remove roadside bombs as they push forward.

He says no paramilitary forces, mostly made up of pro-government Shiite militias, are taking part in the operation. Al-Numan says the Iraqi air force and the U.S.-led international coalition are providing air support to troops on ground and bombing ISIS targets.