By Hader Glang & Roy Ramos

ZAMBOANGA CITY, the Philippines

The Philippines’ military confirmed Sunday that 18 soldiers were killed and 53 others injured in a 10-hour battle with Daesh-linked Abu Sayyaf militants in a troubled southern island province.

Filemon Tan Jr., Western Mindanao Command (WestMinCom) spokesperson, said the fighting in Baguindan village in Basilan also killed five militants, including a Moroccan national identified as Mohammad Khattab and a son of Abu Sayyaf leader Isnilon Hapilon, who carries a $5-million bounty on his head.

He told reporters that soldiers of Joint Task Force Group Basilan were conducting operations when they encountered around 120 Abu Sayyaf members and “intense firefight ensued… that lasted for almost ten hours.”

Another 20 militants were reportedly wounded, including sub-leader Radzmil Janatul, alias "Kubayb".

"Military operations continue as the bandits withdrew and splintered into smaller groups," Tan added.

He described the slain Moroccan as an expert and instructor in bomb-making and an extremist preacher involved in efforts to unite armed groups and kidnap-for-ransom gangs in the archipelago’s south.

Soldiers who sustained injuries were taken to an air base hospital in Zamboanga City, where the bodies of the slain were also transported for proper burial.

According to a list released by the military Sunday afternoon, the death toll among soldiers had risen to 20.

Lt. Gen. Mayoralgo dela Cruz, WestMinCom commander, had earlier applauded his troops for fighting “gallantly” despite “enemy resistance” and the militants’ advantage due to familiarity with the terrain in Basilan.

"We salute our troops as they displayed the finest traditions of soldiery and bravely fought the bandits with utmost valor," he said. "We are truly better for their sacrifice and we will take inspiration from their exemplary service."

A military intelligence source who requested anonymity as he was not authorized to speak with media told Anadolu Agency that casualties on the military side resulted from landmine booby traps that exploded in several parts of the encounter site.

He said the first landmine hit a truck carrying troops, followed by others as soldiers tried to close in on 120 heavily armed Abu Sayyaf fighters.

He added that two of the four soldiers reportedly beheaded were army sergeants.

Defense Secretary Voltaire Gazmin and Armed Forces chief Gen. Hernando Iriberri flew to Zamboanga and Basilan on Sunday to visit wounded troops and meet the ground commanders.

Iriberri told reporters in the city that sporadic fighting was ongoing in Tipo-tipo town.

"There is an encounter going on in the same place... we are pursuing the enemies and conducting succeeding operations," he said.

Nearly a thousand families are reported to have fled three villages near the site of the clashes.

The Abu Sayyaf’s Hapilon is wanted by the Philippine and United States governments on kidnapping and bombing charges, and was indicted in Washington for "terrorist acts against U.S. nationals and other foreign nationals."

Last year, he appeared in a video posted on YouTube in which he and his men swear allegiance to Daesh.

Since 1991, the Abu Sayyaf -- armed with mostly improvised explosive devices, mortars and automatic rifles -- has carried out bombings, kidnappings, assassinations and extortion in a self-determined fight for an independent Islamic province in the Philippines.

It is notorious for beheading victims after ransoms have failed to be paid for their release.