MANILA - Recent bombings in Indonesia and the Philippines appear linked and suggest a resurgence by regional militant group Jemaah Islamiyah, Manila's national security chief said Thursday.

Three recent bomb attacks in the southern Philippine island of Mindanao that left eight people dead bear the hallmarks of JI both in "character and intent", said National Security Adviser Norberto Gonzales.

The bombs used in Mindanao were similar to those used in last Friday's bombings of two luxury hotels in Indonesia's capital that killed seven people and the two countries are coordinating their investigations, he said.

"We cannot disregard the possibility of a JI resurgence in the region," Gonzales told the Foreign Correspondents Association of the Philippines.

"We can easily conclude that the bombings in Mindanao and in Jakarta are connected. The character of the bombs are the same," he said.

Indonesian and Philippine authorities are exchanging intelligence data to track down those responsible for both sets of attacks, he said.

Senior counter-terrorism officials in Indonesia have said the Jakarta attacks appaered to be the work of Islamists linked to JI.

The group's ultimate goal is to unite Indonesia, Brunei, Malaysia, Singapore and the southern Philippines in a fundamentalist Islamic state.

The bombings in Mindanao -- one outside a Catholic cathedral in Cotabato city -- could have been carried out by one of an estimated 20 to 30 foreign JI militants with links to the Abu Sayyaf believed to be in the area, he said.

The Abu Sayyaf is a small group of Islamic militants which has been blamed for some of the worst terrorist attacks in the Philippines.

Pedro Cabuay, a former military general who now heads Manila's National Intelligence Coordinating Agency, said up to 30 JI militants were known to operate on Mindanao.

This group includes Indonesians Umar Patek and Dulmatin, who fled to Mindanao in 2003 after helping carry out nightclub bombings in the Indonesian resort of Bali in which 202 mostly Australian tourists were killed.

The US government, which has been actively helping Southeast Asian governments combat terrorist groups, has offered a 10 million dollar reward for the capture of Dulmatin and one million dollars for Patek.

Cabuay said most of the JI members in the south had been observed on Jolo, a jungle-clad island in the southernmost tip of the Philippines that is also a stronghold of the Abu Sayyaf.

The JI members are believed to be highly mobile and earlier intelligence suggested they had helped the Abu Sayyaf carry out the January abductions of three international Red Cross workers who were subsequently released.

"They are here for some training and assist locals in building bombs," Cabuay said.

Downtown Jolo was bombed on July 7 -- 10 days before the JI attacks on the JW Marriott and the Ritz-Carlton in Jakarta.

Gonzales said JI cells in Indonesia and in the Philippines somehow "have a connection... of an arrangement to some degree."

"It simply means that this group continues to be active in the region," despite an earlier crackdown by Jakarta, Gonzales said.