Police in the Philippines are hunting for five Indonesians suspected of being involved in a deadly bombing in the southern Philippines last week.

Philippine police officials say five Indonesian men conspired with a hit squad from the separatist Moro Islamic Liberation Front, or MILF, to bomb Davao city's port last week, killing 16 people.

Police think the Indonesians are part of the Southeast Asian terror network, Jemaah Islamiyah.

"We are not ruling out anything here, including Indonesians [and] local terrorists," said Isidro Lapena, the police chief in Davao, which is a commercial center in the southern Philippines.

The port blast was the second deadly bombing in Davao in a month. An earlier airport explosion that killed 21 people has been blamed on the MILF.

Philippine military officials and foreign intelligence agencies had earlier reported that the MILF, which has been waging a separatist war in the southern Philippines for decades, has trained Southeast Asian members of Jemaah Islamiyah.

Security experts in the region say Jemaah Islamiyah wants to establish an Islamic state in Southeast Asia. Indonesian police think the group is behind the deadly bombing in Bali last year. About 200 people, most of them foreign tourists, died in that October blast.

There is a large Indonesian community in Davao and its surrounding areas. Many of them are involved in trade. The southern Philippine islands are within a few hours boat ride of the northern Indonesian islands.

President Gloria Macapagal Arroyo has ordered the government to increase security against foreign terrorists. But she has cautioned the police not to arrest or deport foreign nationals "without credible proof" of wrongdoing. Over the past several months, a number of foreigners, mostly from Middle Eastern countries, have been detained or deported for suspected terrorist activities in the Philippines.