MOSUL, Iraq – Iraqi special forces launched a two-pronged assault deeper into Mosul's urban center on Friday, unleashing the most intense street battles against Islamic State militants since the offensive began nearly three weeks ago.
Smoke rose across eastern neighborhoods of Iraq's second-largest city as heavy fighting continued after sundown, with explosions and machine gun fire echoing in the streets as mosques called for evening prayer.
Earlier, columns of armored vehicles wound through the desert to open the new front, pushing through dirt berms and drawing heavy fire as they closed in on the middle-class Tahrir and Zahara districts. The area was once named after former Iraqi dictator Saddam Hussein.
Seven suicide attackers in explosives-laden vehicles barreled toward the troops, with two getting through and detonating their charges, Lt. Col. Muhanad al-Timimi told The Associated Press. The others were destroyed, including a bulldozer that was hit by an airstrike from the U.S.-led coalition supporting the offensive.
The advancing troops also came under heavy fire from mortars, automatic weapons, snipers and anti-tank rockets. At least five special forces troops were killed and an officer and three soldiers were wounded, said an Iraqi military officer who spoke on condition of anonymity because he was not permitted to brief reporters.
"The operation is going well, but it's slow. These kinds of advances are always slow," said Iraqi special forces Cpt. Malik Hameed, as IS fighters could be seen running in the distance to reposition themselves. "If we tried to go any faster we would take even more injuries."
Earlier, at the eastern approach to the city's urban center, militants holed up in a building fired a rocket at an Iraqi Abrams tank, disabling it and sending its crew fleeing from the smoking vehicle. The advance in that area then stalled.
An Iraqi television journalist traveling in a Humvee was wounded in one of the suicide car bomb attacks.
The push began as dawn broke with artillery and mortar strikes on the Aden, Tahrir, and Quds districts, just west of the special forces' footholds in the Gogjali and Karama neighborhoods, al-Timimi said. Both sides opened up with small arms and mortar fire after an artillery barrage by the special forces.
Later, the regular army's ninth division, which has been following the special forces, moved into the eastern Intisar neighborhood, said an officer from the unit who spoke on condition of anonymity because he was not authorized to speak to the media.
The Islamic State group is fighting to hold Mosul as Iraqi forces and allied Kurdish troops squeeze in from all directions with U.S.-led coalition support, mostly from airstrikes and reconnaissance.
On Tuesday, Iraqi troops entered the city limits for the first time in more than two years, after a demoralized Iraqi army fled the city in the face of the Islamic State group's 2014 blitz across large swaths of territory in Iraq and neighboring Syria.
The Iraqi forces still face weeks if not months of urban warfare as they work their way neighborhood by neighborhood in house-to-house battles through dense warrens of booby-trapped buildings.
More than 1 million civilians still remain in the city, complicating the advance. IS militants have driven thousands of residents deeper into the city's built-up areas to be used as human shields, while hundreds of others have fled toward government-controlled territory despite the uncertainty of resettlement in displacement camps.
At a road junction in the town of Bartella on Friday, convoys of cars queued up to go through checkpoints that led to displaced persons camps.
"We suffered and there was bombing and heavy shelling. We didn't feel safe," said Mahmoud Mahdi, who was fleeing the now government-held Gogjali neighborhood. "Everybody is displaced and walking around in this heat. It is exhausting."
Mosul is the last major IS stronghold in Iraq, and expelling the militant group from the city would be a major blow to the survival of its self-declared "caliphate" that stretches into Syria.
Iraqi forces have made uneven progress in closing in on the city since the operation began on Oct. 17. Advances have been slower from the south, with government troops still some 20 miles (35 kilometers) away. Kurdish fighters and Iraqi army units are deployed to the north, while government-sanctioned Shiite militias are sweeping in from the west to try to cut off any IS escape route.
On Wednesday, one of the leading Shiite militias, the Hezbollah Brigades, said its fighters had gained control of a highway linking Mosul to the Syrian city of Raqqa, the de facto capital of the militants' self-proclaimed caliphate.
The militias' umbrella group, the Popular Mobilization Units, say they will not enter Mosul and will instead focus on retaking Tal Afar, a town to the west that had a Shiite majority before it fell to IS in 2014.
Meanwhile, the U.N. Office of the Commissioner for Human Rights in Geneva said it had new reports of mass killings by IS in Mosul.
Spokeswoman Ravina Shamdasani said the agency had received reports that IS killed 50 of its own militants on Monday at the Ghazlani military base for alleged desertion.
She said her office also had reports that four women were killed and 17 other civilians wounded in airstrikes on Wednesday in Mosul's Quds neighborhood. She also cited a report that IS has been holding nearly 400 women captive in the town of Tal Afar, near Mosul.
Associated Press writers Brian Rohan in Baghdad and Jamey Keaten in Geneva contributed to this report.