Gloria Arroyo is pursuing a policy of 'active defence' against the MILF

Army officials said the raids, which took place took place on the island of Mindanao, were carried out to prevent the rebels regaining territory around the town of Pikit, which was captured by the army last month.

The renewed fighting came as President Gloria Arroyo sent a special envoy to meet Malaysian Deputy Prime Minister Abdullah Ahmad Badawi in the hope of restarting peace talks with the rebels.

The envoy, ex-foreign secretary Roberto Romulo, is expected to discuss Malaysia's offer to act as host for the talks.

On Wednesday President Arroyo confirmed that fighting had restarted in the Buliok enclave, near the town of Pikit.

The MILF rebels were forced from the area last month, when the government launched a military offensive after accusing the rebels of harbouring terrorists.

Army chief Lieutenant-General Narciso Abaya said on Wednesday that the rebels had blasted the area with mortar and rocket fire, but were repulsed by helicopter gunships and attack planes.

President Arroyo asked the MILF rebels to renounce what she described as "terrorism".

She stressed that the military would maintain its policy of "active defence", which involves aggressively pursuing the MILF.

The 12,500-strong rebel group has waged a 25-year-old campaign for an Islamic state in the southern Philippines.

Despite signing a peace agreement with the government, sporadic violence continues to erupt between the two sides.

Postponed US visit

A spokesman for President Arroyo announced on Thursday that she had postponed a scheduled visit to the United States because of the threat of war in Iraq.

President Arroyo spoke with US President George Bush late on Wednesday and they "mutually agreed" to put off the trip, spokesman Ignacio Bunye said.

"Both leaders will have added responsibilities should hostilities occur, and they need to bring to bear the full weight of their attention on these matters," he said.

While Ms Arroyo supports the US-led war on terrorism, her government faces opposition at home from Muslim rebel groups.

In the event of a war with Iraq, she will also need to turn her attention to the safety of about 1.3 million Filipinos working in the Middle East.