Iraqi security forces rest at their base in the al-Haykil area near Fallujah on June 10. (Ali Arkady/VII for The Washington Post)

Iraqi forces radioed the U.S.-led coalition for air cover as they evacuated their casualties: One member of a police bomb-disposal team had been killed and two others had been wounded as they dismantled part of the complex network of booby traps on the edge of Islamic State-held Fallujah.

Another team pushed on, attempting to clear a recently secured neighborhood on the southern side of the city, the occasional explosion kicking orange dust into the air as part of the painstaking work. But a few hours later, that team was hit by an explosion as its members defused a bomb, and two soldiers were seriously injured.

“It’s one of the worst jobs in the entire world,” Col. Arkan Fadhil of Iraq’s special forces said after radioing for another team, this time a group of tribal fighters trained by the United States in bomb-disposal techniques. On Friday morning alone, Iraqi engineering teams had encountered 25 improvised bombs in a stretch of just 500 feet, he said.

The Islamic State has had more than two years to barricade itself into Fallujah, the city west of Baghdad that was the first in the country to fall to the militant group. After launching an offensive for the city last month, Iraqi special forces are now within two miles of the city’s center, but extensive tunnel networks used by the militants and deadly roadside bombs are slowing their progress.

In a group of semi-constructed buildings on the city’s outskirts, Iraq’s elite counterterrorism forces have set up a makeshift base. Bullet and mortar holes pockmark the skeletons of unfinished concrete structures, where soldiers and police officers use unfinished rooms to lie down and rest, blankets laid out on the floor next to piles of sandbags.

The Post’s Hugh Naylor is on the front lines of the fight to remove the Islamic State from the Iraqi city of Fallujah. The assault is being led by the military, police and elite counterterrorism forces, but powerful Shiite militias are eager to be involved, as well. (Hugh Naylor/The Washington Post)

It’s a high-stakes fight for Iraqi Prime Minister Haider al-Abadi, with the battle distracting from a political crisis that has brought regular demonstrations and seen protesters ransack parliament and his office, demanding reform. Iraqi commanders have also argued that clearing the city is a priority because of its proximity to Baghdad, just 45 miles to the east.

Lt. Gen. Abdulwahab al-Saedi, head of the Fallujah operation, pointed out the position of his men in the distance in the Shuhada neighborhood.

“See the communications tower,” he said. “They are there.”

The sound of machine-gun fire and explosions rang out. The special forces fighters from the police and counterterrorism units had reached Street 40, about two miles from the city’s center on the southern side, he said. On Saturday, the Iraqi army also announced that it had recaptured two neighborhoods east of the city.

It’s an important fight that no one expects to be easy.

“It’s considered symbolic for Daesh,” Saedi said, using a term for the militant group derived from its Arabic acronym. “It was the first city that fought against the Americans, and extremist Muslims have made it their shrine.”

Nearly 100 U.S. Marines died and hundreds were wounded in a six-week battle for the city 12 years ago, their bloodiest fight of the Iraq War.

“We want to show the Americans we are able to do it, but with their support, of course,” he said.

Over his radio, Fadhil received word from the U.S.-led coalition that a medium machine-gun position had been spotted from the air.

“Are they on the third building to the east?” Fadhil responded.

“They are on the fourth building to the east,” came the reply in an Australian accent.

“Can I call a strike on that, please?” Fadhil asked.

A few minutes later, it came, sending a pillar of smoke above the city.

The Islamic State has built an extensive network of tunnels to hide from the strikes. Meanwhile, its fighters set fires to obscure their positions from the jets overhead.

“The tunnels go right through the city,” said Brig. Gen. Ali Jamil of Iraq’s counterterrorism forces. “They use them for transportation, away from the airstrikes, but also to ambush our forces,” he said.

The warrens of tunnels have rooms and lighting, Jamil said. One that was recently discovered stretched for about a half-mile. The Iraqi forces do not know how far others they have found extend, because they blow up the entrances so the tunnels can’t be used.

Some have been booby-trapped. This past week, an M1 Abrams tank was blown up. It either was hit by a large roadside bomb or driven over an explosive-rigged tunnel, Fadhil said. Whichever it was, the effect was devastating.

“The Abrams was in three pieces,” Fadhil said. “It was a huge explosion.” All four members of the crew died.

Soldiers hope the complexity of the barricades will ease as they move into the city. The area they are traversing now has been a defense line for two years. Barricades closer in are likely to have been put together more hastily.

Still, no one expects the city to fall easily. The presence of tens of thousands of civilians further complicates matters. The United Nations recently said that it thinks 90,000 remain.

Islamic State militants have gunned down people trying to flee Fallujah, according to Human Rights Watch and Iraqi officials. Meanwhile, pro-government Shiite militia forces have allegedly beaten and tortured detainees.

Saedi faces a challenge in keeping Iraq’s Shiite militias, which have long encircled Fallujah, out of the battle. For them to enter the Sunni-dominated city would risk igniting sectarian tensions.

Commanders here said they think between 300 and 900 militants are in the city. But no one really knows.

Although some have managed to escape, for those trapped inside, it is a case of “fight or die,” Saedi said.

Mustafa Salim contributed to this report.

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