KORONADAL CITY, Philippines--A suspected member of an extortion group blamed for the series of bomb attacks on bus firms operating in the region escaped from his detention cell in Kidapawan City in North Cotabato on Sunday, Governor Jesus Sacdalan has revealed.

Sacdalan told the Philippine Daily Inquirer by phone that the jailbreak of Musali Cado, charged with multiple murder, and another companion facing theft charges, Samuel Nacario, was discovered by prison guards shortly before 7 a.m.

"They sawed off the window grills," Sacdalan added.

Sacdalan said Cado, a bomber of the Al-Khobar, a group linked to Abu Sayyaf militants, was arrested in 2008.

Provincial prosecutor Al Calica said officials would seek criminal charges the against the guards at the jail, the Associated Press reported.

The Al-Khobar gang, led by Salahuddin Hassan and Abdul Malik Salih, has been blamed for attacks against units of the Weena Bus Co., Yellow Bus Co. and Metro Shuttle, in which nearly two dozen people have died since 2006.

In February 2008, heavily armed men believed to be members of the separatist Moro Islamic Liberation Front, raided the North Cotabato provincial jail and freed three suspected bombers and 46 other inmates.