Mount Mayon in Albay province of the Philippines (Photo: AFP/VNA)

Hanoi (VNA) - Mount Mayon in Albay province of the Philippines again spewed ash on November 26, and authorities issued alert level 2.

In a bulletin issued on the same day, the Philippine Institute of Volcanology and Seismology (Phivolcs) said two phreatic eruptions were observed between 7:59 am and 8:05 am.

“The events generated grayish to grayish white ash plume that rose 300 to 500 meters above the summit before drifting southwest," Phivolcs said.

Mayon volcano has been under Alert Level 2 since late March this year, which means "a moderate level of unrest."

Phivolcs warned that "sudden explosions, lava collapses, pyroclastic density currents or pyroclastic density currents (PDCs), and ashfall can still occur and threaten areas in the upper to middle slopes of Mayon."

It reiterated that people should not be allowed to enter the 6-kilometre-radius permanent danger zone and the 7-kilometer-radius extended danger zone stretching from Anoling, Camalig, to Sta Misericordia, Sto Domingo.

The 2,464m high mountain, located on Luzon island in Albay province, is the most active volcano in the Philippines. Over the past 400 years, the volcano has erupted 51 times. The eruption in 1814 killed over 1,200 people and occluded three towns.-VNA