MANILA, Philippines (AP) _ Five Muslim rebels have surrendered on a southern island where the Philippine military is trying to rescue five hostages and destroy the rebel group, the military chief said Monday.

The surrenders are an indication the Abu Sayyaf guerrillas are tiring from the military attack on Jolo island, armed forces chief of staff Gen. Angelo Reyes said.

``We expect more surrenders from them because of the hardship they have been encountering,'' Reyes said.

Police recently seized a speedboat in Parang town that the guerrillas were apparently planning to use to escape from the island, provincial police chief Candido Casimiro said.

The five guerrillas surrendered in two separate groups on Sunday, Reyes said. All were followers of Ghalib ``Robot'' Andang, an Abu Sayyaf commander who led the abduction of 21 tourists and workers from a Malaysian diving resort in April. The rebels later abducted dozens more hostages.

Most of the hostages have been released after the payment of more than dlrs 15 million in ransom by Libya and Malaysia, negotiators say. The rebels are still holding five hostages _ three Malaysians, an American and a Filipino.

Governor Abdusakur Tan said the offensive has forced more than 80,000 people to flee their homes in the hills and mountains of Jolo, where air force planes and government troops are bombarding the rebels with rockets, artillery and gunfire.

Military officials say the assault is likely to take at least two more weeks.

The rebels say they are fighting for a separate Islamic state in the southern Philippines, but the government regards them as bandits.