One such cell organized by Jemaah Islamiyah, which has been linked to Osama bin Laden’s al-Qaeda network, is known as Rajah Sulaiman, Central Luzon police director Chief Superintendent Oscar Calderon said, citing intelligence reports.
Calderon was quick to add, however, that so far there have been no indications that these groups are capable of launching terrorist attacks.
"We are monitoring purchases of explosive materials that could be accessed by such suspects and, so far, we have no cause for worry," he said.
He did not say how many cells Jemaah Islamiyah has already formed. "We cannot ignore the information we have been gathering about such extremist groups," he said without elaborating.
Pampanga police chief Senior Superintendent Rodolfo Mendoza, former Pangasinan police chief, said Rajah Sulaiman now has a base in the town of Anda in Pangasinan.
"They were already organized in Anda when I was still in Pangasinan. We have identified their previous contacts based in Metro Manila," he said.
Many of Rajah Sulaiman’s members were former Christians who were told by their recruiters that by converting to Islam they "reverted" to the religion practiced by Filipinos prior to the arrival of Spanish colonizers in the 16th century, Mendoza added.
Calderon said they suspect that Jemaah Islamiyah would try to recruit members among Muslims from Mindanao.
"It seems that the suspects are finding little difficulty in their movements because of the pervasive bias against Muslims in Central Luzon, where most people are Christians. In this case, such bias seems to be working in our favor," he said.
The Philippines is Asia’s bastion of Christianity with its 80 million Filipinos predominantly Catholic. Its Muslim minority is concentrated in the south.
In May, police arrested nine suspected terrorists, all Filipinos, in the towns of Anda and San Clemente, also in Pangasinan.
Officials said the suspects had been planning to launch attacks to mark Labor Day and were being trained by a group with links to Jemaah Islamiyah. The suspects denied the allegations.
Police blame Jemaah Islamiyah and the al-Qaeda-linked Abu Sayyaf for the bombing last week in Zamboanga City that killed a US soldier and two Filipino civilians.
According to US and regional intelligence officials, Jemaah Islamiyah was involved in the 2000 Rizal Day bombings, in which scores of people were killed or wounded in a series of bomb attacks across Metro Manila, including one across the US Embassy.
Early this year, Philippine courts convicted two Indonesians, both suspected members of Jemaah Islamiyah, for illegal possession of explosives. Officials say the two, Fathur Rohman al-Ghozi and Agus Dwikarna, were involved in the Rizal Day bombings.
The group was also allegedly responsible for the bomb attack on a Philippine ambassador in Jakarta in 2000, in retaliation for a massive Philippine military offensive against the Moro Islamic Liberation Front, which was recently linked to al-Qaeda.
Citing interviews with US and regional intelligence officials, US news reports earlier said Jemaah Islamiyah’s activities in the Philippines and in neighboring countries are part of al-Qaeda’s efforts to move its operations to Southeast Asia and attack US targets in the region.