The military's Southern Command ordered an investigation yesterday into a grenade attack on a mosque in Mindanao that left one Muslim preacher dead and more than a dozen worshippers wounded, many seriously, an official said. A masked assailant tossed the grenade early on Friday into the mosque in Lambayaong town in Sultan Kudarat province, the military said.

"Military authorities are investigating. We are helping the police investigate this attack," said Col Fredesvindo Covarrubias, commander of the armed forces Civil Relations Group. No individual or group has claimed responsibility and the motive for the attack remains unknown, Covarrubias told reporters in Zamboanga City.

Last week, suspected Moro guerrillas bombed a Catholic church in Parang town in nearby Maguindanao province and another church in Cotabato City. It was unknown if the Friday mosque attack was connected to the twin bombing of Catholic churches. Both Sultan Kudarat and Maguindanao are predominantly Muslim provinces, where Moro Islamic Liberation Front (MILF) forces have previously attacked Christian targets, including a Catholic-run radio station in Cotabato City. The smaller rebel group, Abu Sayyaf, has also in the past bombed Catholic churches and assassinated priests in Sulu and Tawi-Tawi in the southern Philippines.