Glowing-red lava spurted in a fountain and flowed down the Philippines' most active volcano.
The eruption has sent more than 34,000 villagers fleeing to safety and prompted police to set up checkpoints to stop tourists from getting too close.
The Philippine Institute of Volcanology and Seismology said the lava flowed as much as two kilometres (1.2 miles) from the often cloud-shrouded crater of Mount Mayon, while ash fell on several villages in northeastern Albay province.
Officials strongly advised people not to venture into a danger zone about six-to-seven kilometres (3.7 to 4.3 miles) around Mayon, including residents who want to check their homes, farms and animals, and tourists seeking a closer view.
The Philippine Institute of Volcanology and Seismology (Phivolcs) said it had recorded nine more tremors, four of which accompanied lava fountains, as pressure leads to lava flows and ash plumes.
It reiterated that the activity signified a possible hazardous eruption within weeks or even days from the near perfectly cone-shaped volcano.