Philippine Air Force planes bombarded Muslim rebel positions Wednesday in a southern province in a bid to flush out a commander who led deadly attacks last week, a military report said.

The bombings were focused on the encampments of Moro Islamic Liberation Front (MILF) commander Abdullah Macapaar, also known as Commander Bravo, in Lanao del Norte province, 810 kilometres south of Manila.

The airstrikes occurred a day after five MILF rebels were killed and 10 wounded in a three-hour clash with government troops in Piagapo town in Lanao del Norte. Five soldiers were also wounded in the fighting.

Military command chief Brigadier General Jorge Segovia said authorities were trying to verify reports that Bravo was wounded in the offensive and was being treated in the predominantly Muslim city of Marawi in nearby Lanao del Sur province.

"We have yet to receive confirmation on the report," he said.

Segovia said the military offensive was expected to continue throughout the Islamic holy month of Ramadan, which starts September 1.

"We have not attained our objective, so the operation will continue," he said.

Bravo and hundreds of his men attacked five towns in Lanao del Norte earlier in the month, resulting in the killing of at least 40 people with scores wounded.

Another military offensive was ongoing in nearby Maguindanao province to flush out another MILF commander, Ameril Umbra Kato, who occupied 15 villages two weeks ago in North Cotabato province, triggering a three-day firefight with government security forces.

Amid the military offensive, presidential peace adviser Hermogenes Esperon said the government and the MILF peace panels were preparing to hold a meeting to discuss the mandate of an international team monitoring a 2003 ceasefire.

The international monitoring team's (IMT) mandate is to expire Sunday, raising fears of more fighting.

"Without the IMT, it would be very difficult although we can maintain the ceasefire and the peace process itself," Esperon said. "At this time, we are setting up the necessary meetings. The venue will either be in the Philippines or Kuala Lumpur."

Esperon said Malaysia would facilitate the meeting to discuss the extension of the mandate of the monitoring team, which is composed of troops from Malaysia, Brunei, Libya and Japan.

The National Disaster Coordinating Council said close to 340,000 people have been displaced in the hostilities that started after the Supreme Court blocked a controversial territorial deal between the government and the MILF.

The botched agreement on ancestral domain would have added 735 villages to the existing six-province Muslim autonomous region on strife-torn Mindanao, the Philippines' main southern island.

The Philippine government eventually scrapped the deal amid strong opposition by Catholic politicians, but the MILF insisted that the government should honour the agreement, which was negotiated for more than four years.