The military has intensified rescue operations in Basilan following Monday's clash between soldiers and Abu Sayyaf guerrillas believed to be holding two American hostages and several Filipinos in the jungle of Sumisip town.

Col Hermogenes Esperon, army commander in Basilan, said yesterday that Monday's clash killed a still undetermined number of gunmen in Sumisip's Baiwas village. He said soldiers recovered the body of a rebel and an R15 Armalite rifle.

"Troops are in the area and pursuit operation is going on in the hinterlands, where the Abu Sayyaf are believed to be holding the hostages," he said, without elaborating.

One lumberjack was killed and two others were missing when suspected Abu Sayyaf gunmen attacked them yesterday on a remote village in Lantawan.

Admadul Pangambayan, Basilan police chief, said the attack occurred shortly before 7am in Calugusan village, and that the body of Jason Gregorio has already been recovered. He added that government forces and militiamen are still searching for the two missing persons.

The town is a known lair of Abu Sayyaf guerrillas believed behind the raid last month on Balobo village where they beheaded 10 Christian farmers.

Meanwhile, a local official said at least 15 civilians were believed to have been killed in fighting between soldiers and Muslim rebels hiding in a village in the southern Philippines. "A barangay (village) official came to us and said 15 civilians were killed... eleven of them were said to be minors (under 18)," provincial government spokesman Cris Puno said.

Police quoted travellers from the area as saying the guerrillas used villagers as "human shields" during the running gunbattle on Monday in the island's Sumisip municipality.

But the MILF said 19 villagers were killed on Monday when soldiers indiscriminately fired into the village. Soldiers also arrested six residents, MILF spokesman Eid Kabalu said. The military said it had no reports about the killing of civilians but confirmed there had been clashes in the Sumisip area in recent days.

Provincial government spokesman Puno said the governor had sent a team to the area to verify the report and help residents, but had not been able to enter the village because of military operations.

"I cannot confirm (the deaths) until we hear from our team. But they could not penetrate the village because they might be hit by crossfire," Puno said. About 300 families have fled since Monday's clashes started, he said.