Iraqi forces attempt to seize control of bridge in Mosul to retake the city.

MOSUL, Iraq (Reuters) - Iraqi forces backed by the United States made further advances on Sunday in western Mosul, attempting to seize control of a bridge over the Tigris River that connects the government-held area in the east of the city with the center of the offensive against remaining militants on the other flank.

The bridge is the southernmost of the five that cross the Tigris River in the city. All were damaged by airstrikes from the US-led coalition, and later by Islamic State fighters trying to protect the side of the city they control.

"The bridge is very important," said Colonel Falah al-Wabdan of the Interior Ministry's Rapid Response Unit. The battalion is one of two forces leading the campaign in western Mosul. "The bridge is about 400 meters away. By the end of the day you will hear that our forces have arrived there."

Army engineers plan to rebuild the bridge to allow troops to bring in reinforcements and supplies from the east side of the city.

Iraqi forces captured eastern Mosul in January after 100 days of fighting. A week ago, they launched an offensive against neighborhoods located on the other side of the river.

If the government forces defeat the Islamic State in Mosul, they will have defeated the Iraqi branch of the caliphate, declared in 2014 by leader Abu Bakr al-Baghdadi on Iraqi soil and in Syria. The US commander in Iraq stated that he believes the forces will recapture Mosul and Raqqa, an ISIS stronghold in Syria, within six months.

The army, police, and counterterrorism and rapid response units are attacking ISIS in Mosul, with air and ground support from the US-led coalition. Hundreds have fled toward government forces since Thursday, and at least 1.200 by Sunday morning, according to a rapid response official.

(By Stephen Kalin)