MANILA: At least 14,000 people evacuated from around a volcano spewing lava and noxious gases in the central Philippines may remain displaced from their homes for months, authorities warned on Tuesday.

Incandescent lava was seen flowing slowly from the mouth of the 2,462-metre (8,077-foot) Mayon volcano, which was placed on a high alert level last week following seismic tremors and hundreds of rockfall events.

"Based on our previous experiences, this volcanic activity may persist for a few months," Teresito Bacolcol, chief of the state volcanology and seismology agency, told DZMM radio, adding that residents usually living within a 6 km (3.7 miles) radius of the volcano would have to stay in evacuation centres.

Roughly 14,000 people have been evacuated and are sheltering in schools and community centres, disaster agency data show.

Larry Llenaresas, a community leader in Albay province, told DZMM radio there was a need for more food and drinking water for the displaced.

Authorities said people living further away from the volcano should also be ready for possible evacuation, with the police placing checkpoints to prevent residents from returning.

"We will make sure evacuees cannot return until they are advised to do so," police regional director Westrimundo Obinque told reporters.

Mayon is a tourist attraction because of its near near-perfect conical shape.

Dorothy Colle, a provincial tourism official, said while the no-go zone was being enforced, people were still flocking to observation stations to witness lava flows, which appear particularly bright at night.

Mayon is among the most active of the Philippines' 24 volcanoes, having erupted more than 50 times in the last four

centuries. Its most destructive eruption came in February 1841

when lava flows buried a town and killed 1,200 people.

The Philippines is in the Pacific "Ring of Fire," where volcanic activity and earthquakes are common.