The Philippine military chief said Monday that three leaders of Islamic State-linked militants who besieged a southern city have been killed in months of fighting but two others, including one of Asia’s most wanted terror suspects, were still alive and leading a final stand.

Military chief of staff Gen. Eduardo Ano said about 10 foreign militants, mostly Malaysians and Indonesians, were still fighting together with a few dozen local militants in a lakeside community in Marawi city after a series of battle setbacks.

Gen. Ano and Defense Secretary Delfin Lorenzana presented in a news conference a Catholic priest, Father Teresito Soganub, who they said was rescued along with a teacher by troops late Saturday after a mosque used as snipers’ post and bomb-making area by the militants fell after a five-hour battle.

“Pray for me for my healing and recovery,” said the 51-year-old Soganub, who appeared remarkably healthy with a long, white beard.

“No, allow me to die here. I have already accepted my fate,” Gen. Ano quoted Soganub as telling fellow hostages, who once considered making a dash to freedom out of desperation.

At least 45 hostages remain in the custody of a few dozen remaining gunmen and efforts to rescue them are underway, he said.

Citing captured and surrendered militants, Gen. Ano said the military strongly believed Abdullah Maute and two of his brothers who allegedly led the May 23 insurrection in Marawi had been killed. He said a fourth sibling, Omarkhayam Maute, and a top Asian terror suspect, Isnilon Hapilon, are still fighting in the devastated Islamic city.

Troops would not allow Hapilon, who is on a U.S. list of most-wanted terror suspects, to escape from Marawi alive, Gen. Ano said.

The military says at least 869 people, including 673 militants and 149 troops and police, have been killed since the siege began in Marawi, regarded as a center of Islamic faith in the southern third of the largely Roman Catholic nation. Marawi’s central business district and outlying communities now resemble a wasteland of disfigured buildings and houses.

The siege has sparked fears that the Islamic State group may gain a foothold in Southeast Asia by influencing and providing funds to local militants as it suffers battle defeats in Syria and Iraq. The United States and Australia have deployed surveillance aircraft to help Filipino troops battling the Marawi attackers.

Mr. Lorenzana gave assurances that Philippine forces would not allow Islamic State-linked militants to take control of any part of the country.

“We will not allow any of them to get a foothold of even an inch of our sovereign territory,” Mr. Lorenzana said. “Every soldier, airman, sailor, marine, policeman, and coast guard will be true to that commitment up to the point of offering the ultimate sacrifice.”