Iraq still faces grueling combat in Mosul

MOSUL, Iraq -- Layers of hastily erected barricades built from rubble and twisted metal trace Mosul's eastern front line where Iraqi forces and Islamic State group fighters are facing off in the dense neighborhoods and narrow alleyways of the country's second-largest city.

As the operation to retake Mosul enters its second month, Iraqi forces are preparing for prolonged, grueling urban combat.

They have slowed the tempo of their operations, advancing just a few hundred meters at a time. Iraqi forces have gathered troops many times the estimated 5,000 IS fighters in the city.

But hundreds of thousands of civilians still remain in the city.

And the ferocity and magnitude of IS counterattacks and defenses in Mosul is unlike anything Iraqi forces have confronted in the fight against the militant group so far.

As a result, overwhelming force can't bring swift victory, and the campaign is likely to take weeks.

Iraqi forces have advanced the farthest and faced the heaviest resistance in Mosul's east.

Iraq's special forces said they control significant pockets of four of Mosul's easternmost neighborhoods: Zahra, Qadisiya, Tahrir and Gogjali.

The territory measures less than a tenth of the city's total area.

Inside those neighborhoods, Iraqi forces are surrounded by thousands of civilians as they continue to push to the city center.

The presence of civilians already has thwarted the use of overwhelming air power to clear territory.

Iraqi officers said they also worry IS supporters among the civilians are helping the group.

"We control all of this area," Iraqi special forces Maj. Ahmed Mamouri said, speaking in the Zahra district.

"We've cleared the territory of fighters, but some of the civilians still support Daesh," he said, using the Arabic acronym for the Islamic State group.

Mamouri said he believes IS supporters still living in the neighborhood are acting as spotters to aim mortar attacks and scout targets for suicide bombers.

That forces his men not only to focus on the front-line fight, but also look backward and repeatedly screen the thousands living among his men's positions, supply lines and defenses.

When IS initially swept into Mosul in 2014, the group was met with significant popular support from residents, who are overwhelmingly from the Sunni Muslim minority that long has resented marginalization by the Shiite-dominated central government.

That support has eroded under more than two years of harsh militant rule and dire living conditions, Iraqi and coalition officials believe.

Over the past year, Iraqi forces slowly have clawed back territory from IS.

Facing a militant organization that proclaimed itself a state, Iraq's security forces battled IS with conventional military tactics: cutting supply lines, besieging cities and measuring victory in square kilometers.

In Mosul, Iraqi forces are undertaking a much more complex fight.

Mosul is not yet surrounded by Iraqi forces and has smuggling routes and supply lines with IS territory in Syria.

Iraq has mobilized 100,000 troops from the military, as well as tribal and militia fighters, to take on the estimated 5,000 IS fighters inside Mosul.

Also, the U.S.-led coalition has deployed 100 U.S. troops to Iraqi front lines to help.

The coalition has launched more than 4,000 airstrikes the past month, mainly around Mosul, and provided Iraqi forces with surveillance and intelligence.

The individual tactics employed by IS mirror past fights: extensive tunnel systems; large, armored car bombs; snipers; and small units of fighters left behind to fight to the death.