It comes just months after extremists were expelled from the southern city of Marawi
ISIL-linked militants seeking new base in Philippines
Months after being expelled from the southern Philippine city of Marawi, extremists are waging a fresh and deadly bid to capture territory in the same region, the military warned on Friday.
The gunmen have mustered a force of about 200 and fought a series of skirmishes with the security forces this year after government forces retook Marawi in October, said Colonel Romeo Brawner.
"They have not abandoned their objective to create a caliphate in South-East Asia," said Col Brawner, a senior commander for a military task force that has since been protecting Marawi.
"Mindanao is the most fertile ground," he said, referring to the Philippine's southern region. "Our countrymen are more vulnerable [to recruitment]."
Struggling with widespread poverty and armed Muslim insurgencies seeking independence or self-rule, Mindanao must improve poor supervision of madrasas where most young gunmen are recruited, he added.
He said the armed forces were retooling to meet the challenge of the extremist Maute group, which occupied Marawi over five months and has pledged allegiance to ISIL.
Gunmen who escaped during the early days of the US-backed operation to recapture Marawi are leading the recruitment effort, flush with cash, guns and jewellery looted from the city's banks and private homes, Col Brawner said.
The recruits are mostly locals, but an unspecified number of Indonesians, some with bomb-making skills, have recently arrived there, he said.
Mindanao military officials said Maute gunmen murdered three traders in the town of Piagapo, near Marawi, in November.
The military killed three extremists in Pantar, another neighbouring town, on February 8, while police last month arrested three suspects over the Piagapo merchant killings.
The military also reported skirmishes with Maute gunmen in the towns of Masiu and Pagayawan near Marawi last month.
The renewed fighting came after Philippine President Rodrigo Duterte and other political leaders in the Mindanao region warned of a potential repeat of the siege of Marawi which killed more than 1,100 people.
Mr Duterte has imposed martial law over Mindanao until the end of the year in an effort to curb the militants' activities.
Ebrahim Murad, head of the Philippines' main Muslim insurgent group, the Moro Islamic Liberation Front, which signed a peace treaty with Manila in 2014, also warned on Tuesday that extremists were recruiting and could seize another city.
Murad said the 10,000-member Moro Islamic Liberation Front was battling pro-ISIL groups for influence in schools as the extremists worked to infiltrate madrasas and secular universities.
At the same time ISIL gunmen were making their way into the southern Philippines from Malaysia and Indonesia, he added, but gave no estimates.
Speaking separately to reporters on Friday, Col Brawner said the rebuilt Maute forces currently "do not as yet have the capability to launch another attack like what they did in Marawi", though he added this could change.
The siege of Marawi forced the Philippine military, more used to low-intensity jungle warfare against guerrillas, to reorganise and to rewrite their doctrines, with a new emphasis on urban warfare training, he said.
"So [on] the side of the armed forces we are ready for another Marawi siege, whether it happens in Marawi or elsewhere," Col Brawner said.