Getting your Trinity Audio player ready...

The Philippines’ most active volcano oozed lava and shot up plumes of ash Tuesday, forcing thousands of people to evacuate their homes and face the possibility of a bleak Christmas in a shelter.

After ash explosions, state volcanologists raised the alert level on the cone-shaped, 8,070-foot Mayon volcano overnight to two steps below a major eruption.

Dark orange lava fragments glowed as they trickled down the mountain slope overnight. Renato Solidum, head of the Philippine Institute of Volcanology and Seismology, said the activity could get worse in coming days.

“It’s already erupting,” Solidum said.

More than 20,000 people were moved to safety by nightfall Tuesday, said Gov. Joey Salceda of Albay province, where Mayon is located about 210 miles southeast of Manila.

Residents in Albay are used to moving away from Mayon. Nearly 50,000 people live in a 5-mile radius around the mountain, and some villages were evacuated last month when the volcano spewed ash.

Mayon last erupted in 2006, and about 30,000 people were moved. Another eruption in 1993 killed 79 people.

Mayon’s most violent eruption, in 1814, killed more than 1,200 people and buried a town in mud.