More than 39,000 of the 50,000 people living in farming communities in the fertile foothills of Mayon have so far been relocated since the mountain began spewing lava, steam and ash Monday.

But with signs that the 2,460m volcano was preparing for a major explosion, the evacuees have been told to prepare "for an extended stay of up to three months or four months in camps," said Cedric Daep, public safety and emergency chief in Albay province where Mayon is located.

He said a 24-hour curfew has been imposed in an eight kilometre (five mile) radius danger zone amid reports that locals were returning to check on their homes and farms during the day.

The Philippine Institute of Volcanology and Seismology said it recorded a total of 248 volcanic quakes from Mayon on Friday, including at least 50 caused by minor eruptions.

The institute has raised a level-three warning on a five-point scale for Mayon, indicating increased activity that may lead to a major eruption. Volcanologists said two lava domes were spotted in the crater, indicating a build up of pressure.

AFP