The Philippines’ most active volcano has shown signs of imminent eruption, forcing thousands of people on the main island of Luzon to evacuate.

Authorities upgraded the alert level at the Mayon volcano in the southern part of Luzon to “level 3” Sunday after observing steam eruptions and a bright lava glow.

As many as 3,000 villagers fled their homes while the volcano spewed ash, according to CNN affiliate CNN Philippines.