MANILA: Philippine police and military officials said Monday they were pressing on with a manhunt for about 30 kidnapping suspects after three militants were convicted of the 2011 abductions of an American woman, her teenage son and a Filipino relative vacationing in the country’s south.

A regional court convicted the three Abu Sayyaf militants last week and sentenced them to life in prison for the July 12, 2011, kidnappings of Gerfa Lunsmann, her American son Kevin and her Filipino relative Romnick Jakaria from an island beach cottage off Zamboanga city.

Regional government prosecutor Peter Medalle said the convictions would serve as a warning amid a series of kidnappings for ransom by the Abu Sayyaf of foreign and Filipino hostages, which have raised security alarms in the southern region home to a decades-long Muslim separatist rebellion.

“One of these convicted militants is also known for his bomb-making skills,” Medalle said. “It’s a relief that they would now be put away and not pose any danger to society.”

Police Senior Superintendent Angelito Casimiro of Zamboanga city said government forces were hunting about 30 other militants involved in the kidnappings, including an Abu Sayyaf commander, Puruji Indama, who has been linked to bombings and beheadings.

Army Col. Rolando Joselito Bautista, a military commander in the nearby island province of Basilan, where the three hostages were held in the militants’ jungle encampments, said his forces were working to track down the rest of the suspects, along with other Abu Sayyaf militants wanted for various acts of terrorism.