© Associated PressA huge column of ash shoots up to the sky during the eruption of Mayon volcano Monday, Jan. 22, 2018 as seen from Legazpi city, Albay province
The midday explosion sent superheated lava, molten rocks and steam between 3.5 to 5 kilometers (2 to 3 miles) into the blue sky, and then some cascaded down Mount Mayon's slopes and shrouded nearby villages in darkness, Renato Solidum of the Philippine Institute of Seismology and Volcanology and other officials said.
From the crater, the deadly debris billowed about three kilometers (1.8 miles) down on the southern plank of Mayon toward a no-entry danger zone. There were no immediate reports of deaths or injuries, officials said.
Comment: UPDATE (25.01.18)
Mayon volcano, which has been erupting for almost two weeks in the Philippines, still appears to be swelling with magma under the surface, scientists said earlier today. More than 74,000 people are staying in dozens of emergency shelters as the volcano continues to belch lava, ash and superheated gas and rocks. Officials are worried the eruption may last months, affecting the education, health and livelihoods of people in its shadow.
The Philippine Institute of Volcanology and Seismology said tremors, pyroclastic flows and emissions of sulfur dioxide were detected Wednesday and early Thursday. Lava erupting up to 500 meters (1,640 feet) high was spilling down the slope, with one lava flow extending 3 kilometers (1.8 miles) from the crater. Ash plumes still rising up to 5 kilometers (3 miles) high have spread ash onto farms and towns nearby, darkening the skies and forcing villagers to wear masks.
The institute said GPS and other measurements indicated a sustained swelling or inflation of the mountain surface, which was consistent with magma rising and creating pressure. The alert level for Mayon remains four on a scale of five, indicating a violent eruption may be imminent.
See also: String of earthquakes and volcanic eruptions hits Ring of Fire - at least five events in two days