BARTELLA, Iraq: Iraqi special forces charged into the Mosul battle Thursday with a predawn advance on a nearby town held by Daesh (ISIS), a key part of a multipronged assault on eastern approaches to the besieged city.

The addition of the elite troops, also known as counterterrorism forces, marked a significant intensification of the fight for Iraq’s second-largest city. As they advanced, attack helicopters fired on the militants and heavy gunfire echoed across the plains.

Daesh militants unleashed nine suicide car and truck bombs against the advancing troops, eight of which were destroyed before reaching their targets, while the ninth struck an armored Humvee, Lt. Col Muntadhar al-Shimmari told the Associated Press. He did not give a casualty figure, but another officer said five soldiers were wounded. The officer spoke on condition of anonymity because he was not authorized to release information.

The special forces entered the town of Bartella, a traditionally Christian village that fell to Daesh in 2014, around midday. The fighting thus far has been concentrated in a cluster of towns and villages outside Mosul that are mostly uninhabited and littered with roadside bombs planted by the militants, which has slowed the Iraqi advance.

Lt. Gen. Talib Shaghati said the special forces retook Bartella, about 15 kilometers from the edge of Mosul. But Iraqi forces were facing stiff resistance inside the town shortly before he spoke.

The special forces are expected to lead the way into Mosul, where they will face fierce resistance in an urban landscape where Daesh militants are preparing for a climactic battle. The offensive is the largest operation launched by Iraqi forces since the 2003 U.S.-led invasion, and is expected to take weeks, if not months.The Kurdish forces known as peshmerga, who are also taking part in the offensive, announced a “large-scale operation” to the north and northeast of Mosul Thursday. “The operation will be in three fronts,” the peshmerga said in a statement, and follows recent gains by the Kurds to the east of Mosul and Iraqi security forces to the south.

Peshmerga forces stationed on mountains northeast of Mosul descended from their positions and charged toward the front line.

They used bulldozers and other heavy equipment to fill trenches and moved armored vehicles into the breach after about an hour of mortar and gunfire at Daesh positions below in the village of Barima.

Military operations also appeared to be underway in the town of Bashiqa, northeast of Mosul. Thick smoke could be seen billowing from the town early Thursday. A day earlier, Bashiqa was pounded by airstrikes and mortar fire from peshmerga positions high above.

The U.S. military, meanwhile, said an American soldier died Thursday from wounds sustained in a roadside bomb explosion in northern Iraq. It did not say where the blast took place or if the soldier was involved in the Mosul offensive. It marked the first American death since the Mosul operation began.

More than 100 U.S. special forces are embedded with Iraqi troops and hundreds more are supporting the offensive from staging bases.

Iraqi Prime Minister Haider al-Abadi, speaking by video link to diplomats meeting in Paris, said the Mosul offensive was moving “more quickly than we thought.” He also vowed to protect civilians fleeing the fighting and said the government “will not allow any violations of human rights.” He said most residents of the region have welcomed the advancing forces.

Amer al-Jabbar, a 30-year-old soldier with the Iraqi special forces, said he was happy to be taking part in the assault on Bartella and hoped to avenge two brothers killed while fighting for the security forces.

“I had one brother who became a martyr in 2007 and another who became a martyr in 2014,” he said. “I want to avenge them and I’m ready to die.”

Iraq’s U.S.-trained special forces are seen as far more capable than the mainstream security forces that crumbled as Daesh advanced in 2014.

The special forces advanced in some 150 Humvees decked with Iraqi flags and Shiite religious banners. Ali Saad, a 26-year-old soldier, said the Kurdish forces had asked them to take down the religious banners, but they refused.

“They asked if we were militias. We said we’re not militias, we are Iraqi forces, and these are our beliefs,” he said.