MANILA: Philippine troops killed two leaders of a militant alliance in an operation in southern Marawi City on Monday, the defense minister said, a big boost to a military battling to contain the spread of Islamic State’s radical ideology.

Isnilon Hapilon, Islamic State’s anointed “emir” in Southeast Asia, and Omarkhayam Maute, one of two Middle East-educated brothers at the helm of the militant alliance, were killed in an operation based on information from a recently rescued hostage.“Following their operational plan, they (troops) were able to go this morning... they were killed,” Defence Secretary Delfin Lorenzana told reporters.

“We were able to get a testimony from a hostage. She was able to confirm the presence of Isnilon and Maute in that particular building. That’s the building that we assaulted early this morning.”

Their deaths will be a major win for the military, which has been criticized for its slow progress in retaking Marawi, the country’s only Muslim majority city, and the ease at which rebels laid siege to it on May 23.

Hundreds of thousands of Filipinos have been displaced by the fighting, which the authorities say has killed 813 rebels, 47 civilians and 162 military. Child soldiers and teenagers are among the militant fighters.

The rebel occupation of the heart of Marawi has been the biggest internal security crisis in the Catholic-majority Philippines for years, compounding fears that Islamic State’s ideology and its advanced recruitment methods are more prevalent on the island of Mindanao than was previously imagined.

Another leader, Abdullah Maute, the group’s military commanders, was reported by the army to have been killed in August, though no body was found to prove his death. Lorenzana said the military was trying to locate another rebel commander, Malaysian operative Mahmud Ahmad.

The leaders have been central to the rebels regrouping, re-arming and recruiting after previous clashes over the past two years with the Maute group, a well-funded, family-led extremist group that emerged from relative obscurity.

The Dawla Islamiya rebel alliance is comprised of fighters from the Maute group from Hapilon’s radical faction of Abu Sayyaf, and aided by foreigners from countries that include Malaysia, Indonesia, Singapore and some Middle East states.

Experts say foreigners have been instrumental in recruiting for the movement, preying on disenfranchised youth. END IS NEAR

Lorenzana said the battle for Marawi could be over imminently, adding that 17 hostages were rescued on Monday. He said it was premature to discuss lifting martial law in Mindanao, which is in place until the end of the year.

“The indication here is that the Marawi incident is close to the end. We may announce the termination of hostilities in the couple of days.”

Lorenzana said he and President Rodrigo Duterte postponed a trip to Marawi on Monday when troops informed them an operation to kill Maute and Hapilon was in place.

The insurgents have surprised the military by their organization, combat capability and their endurance of more than 130 days of ground offensives and air strikes from fighter jets, bombers and attack helicopters.

Philippine troops have been supported by U.S. and Australian technical support, including use of surveillance planes.

Rommel Banlaoi, head of the Philippine Institute for Political Violence and Terrorism Research, said Monday’s operation was a “tremendous setback” to the pro-Islamic state groups in the region, but warned the battle against extremism was far from over.

“The death of the two leaders shall not make our law enforcement complacent,” he told news channel ANC.

“We have seen many times in the past, the death of key leaders will not prevent the terrorist organizations from wreaking havoc.” Banlaoi said retaliatory attacks can be expected from deputies of the militant leadership, who would assume control of the networks. He said intelligence should be strengthened, and efforts made to tackle recruitment.