The Philippines has raised the alert level around an erupting volcano after signs magma is rising inside.
Residents in two villages were evacuated from their homes on Saturday after Mayon volcano in Albay province spewed ash thousands of meters into the air.
The first “steam-driven eruption” started at around 5pm local time, with the Philippine Institute of Volcanology and Seismology (Phivolcs) recording an ash column of 2500m high.
Phivolcs has now raised the alert to level 2, which means that the current activity is “probably of magmatic origin, which could lead to more phreatic eruptions or eventually to hazardous magmatic eruptions.”
A further five minute eruption on Sunday morning produced more ash, with villagers reporting a sulphurous smell and rumbling sound.
“The public is strongly advised to be vigilant and desist from entering the 6k-radius Permanent Danger Zone to minimise risks from sudden explosions, rockfall and landslides,” Phivolcs said.
Residents have been urged to protect against inhaling the ash by wearing masks or covering their noses and mouths with damp cloths.
People living outside the danger zone but on the slopes of volcano were warned to take precautions against potential roof collapses due to the weight of ash and rainfall.
Mayon last erupted in 2014, with lava flows forcing thousands of people to evacuate. It was at its most deadly in February 1841, when 1200 people were killed and lava buried a town.
Experts say it has been displaying abnormal behaviour since late last year.
But Cedric Daep, head of the Albay Provincial Disaster Risk Reduction and Management Office, said those in evacuation centres may be allowed to return to their homes later in the day, unless the volcano alert level was raised further.
He said not all residents evacuated live inside the 6-km danger zone.
“We have not reached the critical level,” he said in a radio interview.
“Alert level 3 is what we considered critical, 4 is when eruption is imminent, and 5 is eruption in progress.”