Philippine President Benigno Aquino vowed on Thursday tough action against "enemies of peace" after a spate of bomb attacks in the south which security officials blamed on a new al Qaeda-linked militant group.
A series of bombs since July 26 has killed more than a dozen people and wounded scores on Mindanao island, a reminder of the problems facing the Philippines despite a stellar economic performance this year, with the fastest first-quarter growth in Asia.
"To those who want to challenge the authority of the state, you will feel the full brunt, depth, and might of the state's response," Aquino told a business conference in Davao City, which is on Mindanao.
Aquino said the attacks were a "desperate act", and added: "You will not get in the way of the peace and the stability that will help fulfill the potential of Mindanao".
The Philippines is mostly Christian but has a significant Muslim minority in southern islands.
Various Muslim rebel factions have battled government forces in the south for decades though the main ones are involved in peace talks.
Aquino told reporters he had ordered the security agencies to secure possible targets of bomb attacks and to intensify intelligence operations against the bombers.
He said the security forces had identified three groups behind a recent blast in a nightclub in Cagayan de Oro City, where six people were killed and 40 wounded.
"We're looking at three groups which banded together loosely to carry out desperate acts to block our peace process in the south," he said, without giving details.
Sources in the national police told Reuters a new al Qaeda-linked Islamist militant group called the Khalifa Islamiyah Mindanao-Black Flag Movement was the primary suspect in the bomb attacks.
The group was led by an Afghan-trained Islamic cleric, Ustadz Humam Abdul Najid, and had links with an Indonesian Islamist group, police intelligence sources said.
The Khalifa Islamiyah recruited members of the al Qaeda-linked Abu Sayyaf group, a Muslim rebel group called the Bangsamoro Islamic Freedom Fighters and al-Khobar, a group engaged in kidnapping and extortion, said the security sources who declined to be identified.