JALAWLA, Iraq—Islamic State insurgents have planted land mines and other explosives to stall a Kurdish push to retake this town, an unfolding battlefield strategy that foes describe as built on patience, the element of surprise and a willingness to take losses.
The fighters borrowed the tactic from their predecessors, al Qaeda in Iraq, who used improvised explosive devices, or IEDs, to prevent U.S. forces from retaking ground during the decadelong war that ended in 2011.
The strategy has proved effective. Last week, Iraqi troops were slowed by mines planted along highways into the city of Tikrit, causing a stalemate in a renewed counteroffensive against Islamic State fighters there. Repeated Iraqi military attempts to retake Tikrit, a city of about a quarter of a million approximately 110 miles northeast of Baghdad, have failed.
The Sunni militants were less successful in holding off an offensive to recapture the Mosul Dam, despite mining the area heavily. It slowed the advance of Kurds and other Iraqis, but, backed by American airstrikes, they ultimately pushed the militants out.
From the rooftop of an abandoned gas station in Jalawla on Monday, a Kurdish officer peered through binoculars at figures darting between a cluster of low-slung buildings nearby.
“Once we get the command, we will take the center of the town in 12 hours,” said Lt. Col. Bakhtiar Hama Saleh, who estimated that about 150 Islamic State fighters have been holding back the counteroffensive by Kurdish regional forces known as Peshmerga. “But we have to wait for the mines to be neutralized.”
Hikmat Mohammed Kareem, the regional commander of the Kurdish forces near Jalawla, said two Peshmerga were killed by bullets taking the areas around the town. “Marching to the center of Jalawla, 10 were killed by mines,” he said.
The difficulties illustrate the limits of U.S. air power in helping Kurdish and other Iraqi troops combat the battle-hardened militants.
Clearing mines is a delicate, time-consuming and dangerous process that Kurdish officials say is the main obstacle to what they believe could be a more efficient fight to reclaim territory. U.S. airstrikes can do little to lessen the threat of land mines and booby traps.
While Peshmerga leaders welcomed U.S. airstrikes that last week helped Kurdish forces lead the Iraqi military’s first real battlefield gains against the Islamic State at the Mosul Dam, they complained that the strikes would be of limited use without a U.S. troop presence or advanced mine-removal technology.
On Tuesday, the U.S. announced a seven-nation aid package aimed at resupplying Kurdish forces with arms and equipment.
Iran, the chief rival for American influence in Iraq, has also supplied weapons and ammunition to the Kurds, Kurdistan President Massoud Barzani said at a joint news conference with Iranian Foreign Minister Javad Zarif. Mr. Barzani said Iran was the first country to answer the Kurds’ plea for more arms.
The battle for Jalawla, about 70 miles northeast of Baghdad and 19 miles from the border with Iran, shows how Islamic State has been able to take and hold more than a quarter of Iraq in a lightning offensive that began in early June.
The group has demonstrated a resilience and ability to adapt to the contours of the ground fight. After capturing the major northern city of Mosul at the beginning of their blitz on June 10 with mostly light weaponry gathered in Syria, the militants took advantage of the Iraqi military’s capitulation.
They looted heavy and sophisticated U.S.-made weapons that made their quick advance into other cities nearly impossible to contain. Once Peshmerga and Iraqi forces regrouped, and were supported by limited U.S. airstrikes, the insurgency employed mines and IEDs to hold on to land they had seized.
The insurgents have so far appeared willing to concede the high ground after booby-trapping roads into the center of Jalawla, detonating several that collapsed the Jalawla Bridge. That considerably slowed a ground advance by Peshmerga as the Kurds brought in heavy bulldozers to forge a path circumventing the destroyed bridge. It also bought the insurgents time to replenish their weapons and manpower, extending a fight Peshmerga officials had initially said would be short and decisive.
Propaganda videos from the Islamic State — also known as ISIS — show the Syrian militant stronghold of Raqqa as everything from an execution ground and regime bombing target to a recruiting hub where Western Muslims congregate.
Jalawla is strategically located, bisected by a major highway linking the semiautonomous Kurdistan region to the north with Baghdad, the seat of Iraq’s central government, to the south. It fell to insurgents on June 13 when Iraqi forces capitulated under the militants’ initial assault.
“We hadn’t prepared ourselves for an attack of this scale,” said Mr. Kareem, a top official of the Patriotic Union of Kurdistan, one of two main political factions in Iraqi Kurdistan. “The element of surprise was a big factor.”
The retreat of Iraqi forces was accompanied by an exodus of thousands of residents, emptying the town and giving Islamic State radicals a base to operate unfettered for more than 10 days, Kurdish officials said.
On June 25, the Peshmerga launched a counterattack and claimed the town had been won back. But on Aug. 9, the Islamic State launched another assault that routed the Kurdish forces in a 16-hour battle, leaving 10 Peshmerga dead and many injured.
“They control a 1,050-kilometer [650-mile] border,” said Col. Saleh, referring to the south and west front line leading to Syria where Islamic State has taken hold. “They can move fighters and equipment in and out. They are very patient.”
But Col. Saleh and Mr. Kareem said Saturday’s push to retake Jalawla has given the Peshmerga a tenuous upper hand. Within three days, the Kurdish forces took critical high points in the hilly region, beating the insurgents into a retreat in the center of the town.
“They fight until they die or escape,” said Sgt. Mohamed Hussein Najaf, a Kurdish officer in Jalawla. “They don’t seem to care about taking losses.”
The Peshmerga said their advance was abruptly stopped as IEDs were detonated around them. Two commanders were killed and several troops were wounded as the fighters melted into the town’s center.
“It was not a part of the strategy they had used before here,” said Col. Saleh. “We are not specialized in de-mining, so it forced us to slow down.”
By Monday, Peshmerga forces had fortified the area around the center of Jalawla, setting up more than a dozen makeshift watchtowers on hilltops, positioning tanks around the major highway leading south and using a defunct gas station as a staging area for troops.
They have been unable to push further into the center of the town, using daylight hours to rest, then patrolling at night in the outlying areas they control.
Col. Saleh said he has seen evidence the Islamic State fighters are worn down by the fight, no longer mounting attacks, instead taking a defensive position in the buildings and alleyways of the town.
Col. Saleh also noted a new development in this latest round of fighting for Jalawla that he believes signals a victory for the Peshmerga.
“They are leaving their dead behind,” he said, adding that his unit recovered three bodies. “They wouldn’t do that before.”
Mr. Kareem said U.S. and Western support for Kurdish forces in the form of light weapons and ammunition has been helpful, but added that the Kurds need equipment capable of remotely detonating mines, sparing lives and time.
In Washington, Rear Adm. John Kirby, the Pentagon press secretary, said the supplies include ammunition and crew-served weaponry, which could include machine guns or mortars. He said the supplies will be coordinated with the Iraqi government in Baghdad.
The U.S. had hoped to provide a larger amount of direct aid to Kurdish forces, but the Iraqi government has balked at authorizing such an arms transfer, officials said.
As the American administration considers the possible expansion of airstrikes beyond Iraq to Islamic State’s base in Syria, President Barack Obama cautioned Tuesday that the U.S. must use its power carefully and avoid sending Americans into harm’s way unless absolutely necessary.
U.S. Central Command said it had conducted two airstrikes near Erbil, the capital of the semiautonomous Kurdish region, destroying two armed vehicles and damaging another. The attacks brings the total number of airstrikes in Iraq this month to 98.