MANILA (UPDATED) — The Albay provincial government on Friday declared a state of calamity a day after scientists raised the alarm over the active Mayon Volcano.

The seismology agency said it observed 3 fast-moving avalanches of volcanic ash, rock and gases, known as pyroclastic density currents (PDCs), on Mayon's slopes on Thursday. It placed the volcano under Alert Level 3, which meant "increased tendency towards hazardous eruption."

Mayon's unrest has prompted the evacuation of thousands of residents around its 6-kilometer permanent danger zone and nearby areas, according to local officials.

There are around 4,749 families or 18,184 individuals living within the permanent danger zone, according to the Albay Public Safety and Emergency Management Office.

• Mayon raised to Alert 3: 'Effusive magmatic eruption taking place'

The state of calamity declaration will allow the provincial government to use the P30 million calamity fund to cater to the needs of evacuees, Albay Governor Edcel Greco Lagman said.

But the fund would only last for 15 to 20 days, Lagman said.

Five years ago, Mayon displaced tens of thousands of people after spewing millions of tonnes of ash, rocks and lava.

Phivolcs chief Teresito Bacolcol on Thursday warned that Mayon was ripe for another eruption, which usually happens once every 3 to 10 years.

• Gov't begins evacuation of residents around Mayon, aid positioned: Marcos

Mayon, a near-perfect cone located about 330 kilometers southeast of Manila, is considered one of the most volatile of the country's 24 active volcanoes.

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Meanwhile, Taal volcano, located about 50 kilometers south of Manila, has been releasing sulphur dioxide this week, blanketing surrounding areas in smog and prompting warnings for people to stay indoors.

Steam-rich plumes have been recorded rising two kilometers into the sky, the seismology agency said on Thursday. It has left the alert level at 1.

• Phivolcs: Safe to go to Albay, Taal town on June 10-12 long weekend despite volcanic unrest

Earthquakes and volcanic activity are not uncommon in the Philippines due to its position on the Pacific "Ring of Fire", where tectonic plates collide deep below the Earth's surface.

— With reports from Jose Carretero, ABS-CBN News; Agence France-Presse​

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