Manila - Philippine troops seized a cache of explosives allegedly intended for al-Qaeda-linked Muslim militants holding captive two European Red Cross workers on a southern island, a military spokesman said Saturday. The explosives were confiscated on Friday during a raid on the house of a man suspected to be supplying bomb materials to the Abu Sayyaf rebels in Jolo town on Jolo island, 1,000 kilometres south of Manila.

But the marines and police officers failed to arrest the suspected supplier, who left his house before the raid, Lieutenant Colonel Edgard Arevalo said.

Arevalo said more than 360 kilograms of ammonium nitrate, a banned fertilizer often used in homemade bombs, 25 kilograms of potassium chlorate, 900 blasting caps and other bomb-making materials were seized from the suspect's house.

"Hadji Nahrin Abud Akmad, the reported owner of the house, is an alleged supplier of explosive components to the terrorist Abu Sayyaf group," Arevalo said in a statement.

The seizure "aborted the reported bombing operations that the bandits intend to conduct," he added.

Arevalo said recent military intelligence reports indicated that the Abu Sayyaf rebels were planning "bombing operations ... against civilians and military personnel" to divert attention from the hostage crisis.

Abu Sayyaf rebels abducted three Red Cross workers - Swiss Andreas Notter, Italian Eugenio Vagni and Filipino Mary Jean Lacaba - on January 15.

On April 2, the guerrillas freed Lacaba after 78 days in captivity. Authorities denied rumours that 5.5 million pesos (114,580 dollars) in ransom was paid to the guerrillas for her release.

The kidnappers have been threatening to kill the remaining hostages if government forces did not pull out from a wide area of Jolo.

Authorities have rejected the demand, but dispatched emissaries to the rebels to negotiate a compromise to ensure that none of the hostages were harmed.

Abu Sayyaf rebels have been blamed for some of the worst terrorist attacks and high-profile kidnappings in the Philippines. They have beheaded hostages, including an American tourist abducted in 2001, when authorities failed to meet their demands. (dpa)