The alert level for Mount Mayon, the Philippines' most active volcano, has been raised to four from three amid authorities' warnings about its imminent eruption.
The Philippine Institute of Volcanology and Seismology reported that fountains of lava reached up to 700 meters (2,300 feet) above the Mayon volcano's crater, with massive ash plumes rising up to 3 kilometers (1.9 miles) into the sky on Tuesday night.
About 30,000 people have been evacuated from the Philippines' Albay province, where Mount Mayon is continuing to spew lava and ash.
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CNN cited Mark Dambal, information officer at the Philippines' Office of Civil Defense, as saying that "the evacuation has been ongoing since [the volcano] started showing signs of instability."
"Because of the volcanic activity, the danger zone was extended from six kilometers to eight kilometers [from the volcano's summit]," he explained.
The authorities have, meanwhile, raised Mount Mayon's alert level to four, in a sign that a violent eruption may take place in the coming days. Five is the highest level, indicating that such an eruption is under way.
Mount Mayon, one of the world's most active volcanoes, has already erupted 47 times. Its most devastating eruption in 1814 claimed the lives of at least 1,200 people.