Philippine security forces have killed at least eight militants in an assault on a jungle lair in the volatile south where a Singaporean terrorist was believed to be hiding.

Major-General Cirilito Sobejana, commander of the 6th Infantry Division, told reporters that the Singaporean, Muhamad Ali Abdul Rahiman alias "Muawiyah", was among the "high-value targets" inside the camp on war-torn Mindanao island.

But Muawiyah apparently survived and managed to flee.

The camp appeared to be the main base of a faction of the Bangsamoro Islamic Freedom Fighters (Biff) that government troops overran early Sunday morning (Feb 3).

A 226kg bomb was dropped on the main fortification inside the camp, in Sultan sa Barongis town in Maguindanao province, where Muawiyah and six other foreign terrorists - two Malaysians, two Indonesians and two "Middle Eastern-looking" men - were believed to have been housed, he said.

Referring to Muawiyah, Maj-Gen Sobejana said: "We're still pursuing them, and checking if he was among those hit by the bomb."

He said the bodies of eight militants were recovered.

The assault followed a clash on Saturday in a neighbouring province that killed eight soldiers and three militants in Patikul town, Sulu province. The clash between a Rangers unit and over 100 Abu Sayyaf fighters broke out as security forces pursued those behind an attack on a Roman Catholic cathedral in Sulu on Jan 27 that left 22 dead.

The Biff is a splinter group of the 12,000-strong Moro Islamic Liberation Front, the main secessionist group that has signed a peace pact with the government. The Biff has pursued a more hardline approach, pledging allegiance to the terrorist group Islamic State in Iraq and Syria.

Muawiyah is the chief suspect in the kidnapping of three workers of the International Committee of the Red Cross, in Sulu province, in war-torn Mindanao island in 2009. He fled to Mindanao in the 1990s.

He was first reported killed in an air strike in Jolo province in 2012. This was never verified. He was again said to have died in military offensives across Maguindanao in 2016. Again, there was no confirmation.

Another purported Singaporean militant, Abu Hud Zain, was earlier reported by a senior Philippine military official to have been killed in clashes in Mamasapano on Dec 22. His death and those of four other militants reportedly led to the New Year’s Eve bombing of a Cotabato city mall last year.

But Singapore's Ministry of Home Affairs said in an e-mail on Monday (Feb 4): "Our checks so far indicate that Muhamad Ali Abdul Rahiman, alias Muawiyah, is the only Singaporean known to be currently involved in militant groups operating in southern Philippines.

"There has been no confirmation that Abu Hud Zain, who was reportedly killed in southern Philippines in December 2018, is a Singaporean."

Defence Secretary Delfin Lorenzana said last week that the military is keeping tabs on at least 44 foreign terrorists who have sought refuge in Mindanao. Two are Singaporeans, he said.

Intelligence officials, however, have yet to provide positive identification of any of them. Maj-Gen Sobejana said the Maguindanao camp was run by the Muhajireen Wal-Ansar, also known as the Maguindanao Daulah Islamiyah, a faction of the Biff under the firebrand preacher Esmael Abdulmalik, also known as Abu Turaife.

Correction note: This article has been edited for clarity.