A force comprising thousands of Kurdish and Iraqi army soldiers wrested territory from the Islamic State outside the northern city of Mosul on Monday, facing occasionally fierce resistance at the start of a long-promised offensive to dislodge the extremists from their main stronghold in Iraq.

Kurdish forces moved to take a string of villages east of the captive city while Iraqi army and police units made a push from the south, a rare display of coordination and harmony between rival forces that officials hailed as a significant victory in itself. Kurdish officials said Monday evening that their forces had cleared nine villages in an area measuring roughly 75 square miles, although the degree of their control over the territory remained unclear.

Announced before dawn in a televised address by Iraqi Prime Minister Haidar al-Abadi, the battle is the most ambitious offensive launched by Iraq’s security forces since they were created after the U.S.-led invasion in 2003. As the sun rose and warplanes of the U.S.-led coalition circled overhead, giddy Kurdish soldiers known as peshmerga rode armored vehicles, land movers and even motorcycles on dirt roads toward front lines that seemed to advance by the hour.

“This is a historic day,” Massoud Barzani, president of Iraq’s semiautonomous Kurdish region, said at a news conference Monday evening in which he hailed the unity and shared sacrifice of the combined forces in their first major test.

“We have achieved a lot of success so far,” he said.

The disparate forces pushing to play a role in Mosul’s liberation — including peshmerga, Sunni tribal fighters, Iranian-backed Shiite militias and government units supported by the United States — has underscored the collective sense of trauma and anger in Iraq as the city has suffered under the brutal reign of the Islamic State since it stormed Mosul early in the summer of 2014.

Despite often competing agendas, some of the forces have united to take back the militant group’s most prized remaining territory in the country.

But there are fears that any alliances will only be temporary because of competing interests in and around Mosul, an area rich with ethnic and religious differences as well as oil. Iraqi and U.S. officials have assiduously sought to build up a sense of momentum around the battle for Mosul, partly out of concern that rivalries will rise to the fore and hamper the military effort.

U.S. officials say that American troops, who number more than 5,000 in Iraq, are helping to coordinate logistics, conduct planning and oversee the air campaign, while a smaller number are expected to move forward with Iraqi forces, including the Iraqi army, elite counterterrorism service troops and peshmerga, as they advance on Mosul.

The repeated delays in mounting an offensive on Mosul have been attributed to the special challenges posed by the city, because of ethnic sensitivities and its sheer size. Iraqi officials estimate that at least 1.2 million residents remain in Mosul, raising fears of civilian casualties as well as a mass exodus. Officials are hastily erecting encampments for fleeing residents around Mosul, with relief workers warning that hundreds of thousands of people could soon become displaced.

Military planners have also puzzled over how fiercely the Islamic State would fight to defend Mosul, the most populous city the transnational militant group controls. Over the past two years, residents have spoken about the harsh strictures imposed by the militants, including executions and public floggings, but also the sophisticated fortifications, including trenches, the Islamic State has built to repel any outside attack.

Monday’s battle suggested that the militants would fight to hold their ground — but also that their ability to do so may increasingly be in doubt.

Dozens of peshmerga fighters gathered early Monday in staging areas about 30 miles from Mosul, loading ammunition and supplies into Humvees and other armored vehicles. The soldiers spoke confidently about their mission — to capture a sequence of villages east of Mosul and near the town of Bartala as warplanes with a United States-led coalition carried out airstrikes on Islamic State-held territory nearby.

“We are feeling great. It won’t take more than a day and a half,” said Maj. Bahram Bahjat, a peshmerga commander. He was far less confident, though, about the possibility of liberating Mosul itself, predicting it would take months and be a “bloody battle.”

Armored columns barreled down roads toward villages obscured by smoke from fires set by the militants. Mortar rounds landed near peshmerga engineers building dirt fortifications, but they continued their work, undeterred. A suicide car bomb was struck before it could attack, according to Maj. Shivan Ihsan Saleh, pointing at a towering plume of smoke from a nearby hill.

“This is a dangerous enemy. They use booby traps, suicide bombs. Our information is that they have been digging tunnels,” he said, adding that “our morale is high.”

Kurdish officials refused to comment on casualties. Medics near the front lines said Monday morning that at least one soldier was killed and two were injured in the fighting around Bartala.

Separate from the Kurdish gains, the Iraqi military said more than a dozen villages were captured between the area of Gwer and the south of the city, while two others were seized by police and army forces as they advanced from Qayyarah air base, about 35 miles south of Mosul. The base is the main logistical hub for the Iraqi government’s operation.

But the military official said the villages were largely empty.

“The enemy booby-trapped them and then retreated,” he said. “The advance is very, very slow because of the booby traps.”

Pentagon press secretary Peter Cook said that Iraqi forces were doing better than expected on the first day of the Mosul operation.

Early indications are that Iraqi forces have met their objectives so far and that they are ahead of schedule for this first day,” Cook told reporters at the Pentagon. He said they had reached their first-day objectives by around midday.

“This is going according to the Iraqi plan, but again, it’s early and the enemy gets a vote here,” he said. “We will see whether ISIL stands and fights.” ISIL is another name for the Islamic State.

Some 3,000 to 5,000 Islamic State fighters were estimated to remain within Mosul, Cook said.

Long-awaited Mosul offensive begins

Play Video1:00

Morris reported from Khazir, Iraq. Missy Ryan in Washington, Mustafa Salim in Khazir and Aaso Ameen Shwan in Asquf contributed to this report.

https://www.washingtonpost.com/world/iraqi-attack-on-mosul-begins-with-kurdish-forces-moving-in-from-the-east/2016/10/17/6c6df7d8-93ed-11e6-9cae-2a3574e296a6_story.html?hpid=hp_hp-top-table-main_mosul-540a%3Ahomepage%2Fstory