Philippine rescuers have confirmed four people died after the plane they were in crashed on an active volcano at the weekend, officials said Thursday.

The victims, including two Australians, were on board the Cessna 340 that went missing Saturday morning shortly after taking off for Manila from Bicol International Airport in the central province of Albay, several kilometres from the Mayon volcano.

Carlos Baldo, mayor of Camalig municipality, which overlaps the crash site, said a search and rescue team reached the wreckage on Wednesday and confirmed there were no survivors.

"We found the site, there were no signs of life," Baldo told a news conference on Thursday.

Baldo said 179 people were involved in the operation to carry the bodies down the steep slopes of the volcano.

They hoped to arrive at the base of the mountain by Thursday evening.

The Civil Aviation Authority of the Philippines (CAAP) said the plane's wreckage was on the western side of the volcano, about 3,500 to 4,000 feet (1,070 metres to 1,200 metres) above sea level.

"It's a very difficult terrain," said Albay disaster officer Cedric Daep, warning the retrieval operation could take longer than a day.

"It's steep and there are ridges where only one person can climb at a time."

Manila-based Energy Development Corporation said previously that it owned the plane. The Australians were technical consultants for the renewable energy company.

"Our heartfelt sympathies go to their families and friends during this difficult time," company president Richard Tantoco said in a statement.

The wreckage was spotted on Sunday, but rain, clouds and the risk of a volcanic eruption hampered efforts to reach the crash site.

A rescue team, including veteran mountaineers, began making the steep climb on foot on Tuesday.