Manila - Government troops seized hundreds of sacks of a bomb-making chemical and dozens of blasting caps on a southern Philippine island, a military report said Sunday.

A marine patrol intercepted on Saturday 283 sacks of ammonium nitrates loaded on a motorboat near a wharf in Indanan town on Jolo Island, 1,000 kilometres south of Manila.

A separate marine team raided a house near the wharf a few hours later and recovered 50 pieces of blasting caps, a 45-caliber pistol, three magazines of ammunition and a handheld radio.

Three people were arrested during the operation and were turned over to maritime police for investigation.

Police investigators were determining if the materials seized were intended for illegal fishing or for terror attacks.

Jolo is a stronghold of al-Qaeda-linked Muslim Abu Sayyaf rebels who have been blamed for deadly terrorist attacks in the Philippines. (dpa)