MANILA - Suspected Muslim extremists stormed a provincial jail in the war-torn southern Philippine island group of Mindanao early on Wednesday (Jan 4), freeing over 130 inmates including suspected bomb makers from a secessionist group.

Reports received by radio stations here said at least 132 inmates escaped when about 100 armed men attacked the jail in Armas district in Kidapawan city, North Cotabato province, at around 1am on Wednesday.

The Bureau of Jail Management and Penology said one jail guard and five inmates were killed. Five inmates have been recaptured so far.

Felix Capalla, one of the leaders of the inmates who escaped, told radio network DzBB that three of those who were set free were suspected bomb makers from the 105th Command of the Bangsamoro Islamic Freedom Fighters (BIFF), a secessionist group that has pledged allegiance to the Islamic State of Iraq and Syria (ISIS).

The BIFF is a splinter group of the Moro Islamic Liberation Front (MILF), which is holding peace talks with the government of President Rodrigo Duterte.

Superintendent Peter Bongat, the jail warden, told The Philippine Star: "It was not a jail break. It was a planned rescue of certain detainees."

He said about a hundred men opened fire after cutting the jail's power lines. They then stormed the compound, targeting cells that held high-profile inmates. Only one inmate has been captured so far.

Supt Bongat said there were intelligence reports that an attack on the jail was imminent. The prison staff were reinforced with soldiers last Saturday and Sunday, but they were pulled out by Monday.

Apart from the suspected BIFF fighters, about a dozen drug traffickers were among those who escaped.

Abu Misry Mama, a spokesman for the BIFF, denied that his group was behind the attack, according to a report from Catholic radio station dxMS.