Armed men stormed a provincial jail in southern Philippines early Sunday, freeing 31 inmates including a militant group leader charged over beheading 14 Marines, and two were killed in the escape-and-chase clash, police said.

Around 30 armed men attacked the Basilan provincial jail in Isabela city at 1:45 a.m. (1745 GMT), tore down the jail's gates to free detainees. Jail guards exchanged fire with militants but failed to block them from fleeing. One jail guard and a militant were killed in the ten-minute clash, local police said.

Checkpoints were set up in Basilan following the jail break.

Among those escaped was Dan Laksaw, alias Hai Hassan Asnawi, of the Moro Islamic Liberation Front (MILF) based in Basilan, police said.

Asnawi was suspected of participating in the murder and beheading of 14 Marines captured in a clash between government troops and Al Qaeda-linked militant group Abu Sayyaf in 2007. Asnawi was only arrested last month in the neighboring Zamboanga city.

Basilan is a known hotbed of extremist militants, including the 340-member Abu Sayyaf. The group is blamed for a series of kidnappings and bombings in the Philippines and is now believed to be holding at least three hostages they kidnapped on the island in the past two months.

The jailbreak broke out following a string of violence in the Muslim Mindanao, underscoring the region's extreme volatility.

Fifty-seven civilians were killed in a politically-motivated massacre in Maguindanao province on Nov. 23 while a group of tribal gunmen are still holding 46 villagers as hostages in the Agusan del Sur province, demanding the government to drop murder charges slapped on a tribal leader.