Philippines raises volcano alert again; hazardous eruption seen imminent

An ash cloud hovers over Mayon volcano, as seen from the Bicol Region, Philippines, in this still image taken from a January 21,2018 social media video. Randall Matthew Lorayes via REUTERS

MANILA (Reuters) - The Philippines raised the alert level at its Mayon volcano on Monday after a loud explosion in the wake of increased activity made a hazardous eruption likelier, prompting authorities to close all schools and urge residents to stay indoors.

Mayon, the country's most active volcano, has been spewing ash, lava, and pyroclastic material since Jan. 13, displacing close to 40,000 residents in the central province of Albay.