MANILA - The number of people displaced by an erupting Philippine volcano soared to more than 61,000 by Wednesday, the Southeast Asian country's disaster agency said, as Mount Mayon ejected lava that produced an ash plume 5 km (3 miles) high.

The alert remains just one notch below the highest level of 5 after five more episodes of "intense but sporadic lava fountaining" from the summit crater over a 19-hour period from Tuesday morning, state volcanologists said.

Lava fountains 500-600 metres (1,640-1,970 feet) high lasted between seven minutes and more than an hour and generated ash plumes 3-5 km (2-3 miles) above the crater, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.

Schools were shut in 17 cities and municipalities in Albay and nearby Camarines Sur province, which was also affected by ashfall. Some 56 flights were cancelled because of Mayon, the Philippines' most active and most picturesque volcano.

There were 55,068 residents in temporary shelters, a substantial increase from about 40,000 on Monday. Some 6,165 evacuees were staying elsewhere.

The number of displaced increased after the provincial government expanded the danger zone around the 2,462-metre (8,077-foot) volcano to a radius of 9 km from the Phivolcs-recommended 8 km no-go zone.

Mayon's sporadic eruption, which began on Jan 13, has affected 54 villages in Albay, with a combined population of 71,373 people.

Reuters