Manila - Philippine police forces were placed on heightened alert Tuesday, the eve of the anniversary of the September 11, 2001, terrorist attacks in the United States, a spokesman said.

All police units were told to initiate preventive measures against terrorist activities by local groups, Chief Superintendent Nicanor Bartolome said.

"Based on historical data, some terrorist organizations have been known to launch activities to commemorate some dates and occasions that are significant to their organization," he said.

Manila - Philippine President Gloria Macapagal Arroyo on Tuesday ruled out resuming stalled peace talks with the country's largest Muslim separatist rebel group amid escalating violence in the troubled southern region.

"We will not negotiate with a gun pointed to our head," Arroyo said in a message marking the signing of a peace agreement with a separate Muslim rebel group in September 1996. "Innocent civilians should not be terrorized for crass political gain."

Manila - Rescuers on Tuesday dug up four more bodies from the rubble of two weekend landslides that struck a mining village in the southern Philippines, bringing the death toll to 20.

Nineteen people were still missing in the landslides in Masara village in Maco town, Compostela Valley province, 930 kilometres south of Manila, Mayor Voltaire Rimando said.

Rimando said 23 people were also injured in the landslides, which struck Saturday and Sunday after days of continuous heavy rains.

About 45 homes built on the foothills of a mountain were destroyed when tons of mud and boulders crashed into Masara.

Manila - The Philippine government on Tuesday ordered an investigation into the killings of six civilians during an air assault on Muslim separatist rebels in a southern province.

The civilians, including children and a pregnant woman, were on their way to an evacuation area when their motorboat was hit Monday by rockets fired from a military helicopter gunship.

Prague - Philippine Foreign Minister Alberto Romulo said Monday that he hopes for a peace deal between the Philippine government and Muslim rebels in the country's south by the end of the year.

"I am an optimist," he said after meeting his Czech counterpart Karel Schwarzenberg in Prague. "After we overcome administrative difficulties, we'll have peace."

Romulo said that the rebels were also tired of fighting and there was "a mutual desire" for a solution to the conflict lasting for decades.

Davao City, Philippines - The death toll in two landslides in a mining village in the southern Philippines rose to 14 as rescuers on Monday found more bodies beneath the mud and debris.

At least 16 people were still missing in Masara village in Maco town in Compostela Valley province, 930 kilometres south of Manila, the regional civil defence office said.

Antonio Cloma, operations chief of the regional civil defence office, said rescuers were racing against time in digging through the rubble in hopes of finding survivors.

"We are expecting to find more people buried in the mud, and we have to get them out immediately," he said.

Cloma said four bodies were recovered from the mud and debris Monday morning.