At least 12,800 people were evacuated from the area around the mountain as volcanic activity increased.
Mayon, the Philippines’ most active volcano, has begun spewing lava down its slopes as volcanic activity increases in an area populated by tens of thousands of mostly poor farmers.
Lava began to appear on the slopes of Mayon on Sunday night, and Teresito Bacolcol, director of the Philippine Institute of Volcanology and Seismology, said authorities are alert for further developments.
“What we’re seeing now is an exuberant eruption,” Bacolcol told The Associated Press. “We deal with it every day.”
At least 12,800 people living within a 6 km (3.7 miles) radius of Mayon Volcano have been evacuated since last week. Bacolcol said there is a possibility that the high-risk zone will be expanded if the outbreak becomes severe.
The area below Mayon, about 330 km (205 miles) southeast of the capital Manila, is designated as a permanent danger zone, but many thousands of people continue to live there because they have nowhere else to go.
Volcanologists say the lava is another sign of increased activity, pointing out that there have also been about 260 rockfalls in the past 24 hours, compared to 177 in the past 24 hours. More tremors were also recorded – 21 in the last 24 hours compared to two before.
According to state volcanologists, sulfur dioxide emissions had also tripled on Saturday.
“There is a concomitant health risk of being in the vicinity of the eruption from inhaling sulfur dioxide gas or the particulate matter from ash particles,” Health Minister Teodoro Herbosa said at a news conference on Sunday.
The alert level for the volcano remains at three in the Philippines’ five-level system, meaning there is a tendency for a dangerous eruption to occur within weeks or days.
Albay province, where the cone-shaped Mayon is a popular tourist attraction, was placed on a state of emergency on Friday to allow for faster distribution of disaster relief funds in the event of a major outbreak.
One of 24 active volcanoes in the Philippines, Mayon last erupted violently in 2018, displacing tens of thousands of villagers.
The archipelago lies on what is known as the Pacific “Ring of Fire,” the edge of seismic faults where most of the world’s earthquakes and volcanic eruptions occur. Typhoons and tropical storms are also common and this typhoon is forecast to hit the area later this week.
The country’s most powerful eruption in recent decades was Mount Pinatubo in 1991, which killed more than 800 people and created an ash plume that spread thousands of kilometers.