"The Philippine Embassy may be targeted since the United States embassy in Indonesia has already been closed," a Philippine National Police intelligence report said.
Also among the possible targets are Western diplomats and US interests in Indonesia, the report added.
Three months ago, on Aug. 1, a powerful car bomb went off and seriously wounded 70-year-old Leonides Caday, ambassador to Indonesia, as his limousine was about to enter his residence.
An Indonesian security guard and another person were killed and several people wounded in the mid-afternoon blast.
Caday suffered leg injuries and may not be able to walk for some time. He was discharged from the hospital two months after the attack and is now recuperating in a rented house, heavily guarded by Indonesian security men provided by the Indonesian government.
Indonesian President Abdurrahman Wahid at first blamed the Moro Islamic Liberation Front (MILF), suspecting that the bombing was linked to a Philippine military offensive against the MILF in Mindanao.
The MILF’s headquarters was captured almost a month prior to the bomb attack that nearly killed Caday. He was screaming in pain as passersby pulled him out from his wrecked car.
Wahid later suspected that the bombers were supporters of deposed Indonesian dictator Suharto, out to embarrass his reformist government which is trying to put Suharto behind bars on corruption charges.
But the police intelligence report believes that the blast that nearly killed Caday was linked to the MILF.
Tension in Jakarta remained high after the dropping of corruption charges against Suharto due to his ill health, sparking outrage and riots among Indonesians.
Under pressure from the public, Wahid ordered a retrial, triggering fears of more violence from pro-Suharto followers. Suharto is accused of amassing millions of dollars during his 32-year iron-fisted rule.
Several people were arrested in connection with a Sept. 13 bomb explosion that rocked the Indonesian stock exchange, which authorities said was linked to the Aug. 1 blast.
But, so far, Indonesian police have been unable to pinpoint those responsible for the bomb attack that wounded Caday.
Indonesian investigators initially suspected that Caday was being targeted by the MILF or their supporters in Indonesia, but later believed that the envoy just happened to be at the wrong place at the wrong time.
The Philippine Department of Foreign Affairs had urged some 3,000 Filipinos living in Indonesia to take precaution because of the political instability there.