Glowing lava poured from the Mayon Volcano summit crater as authorities warned of a possible prolonged eruption.

Footage shows spectacular streams of molten material flowing down the volcano's slopes in Albay province on June 13.

In a June 15 bulletin, the Philippine Institute of Volcanology and Seismology said it recorded 306 rockfall events and two volcanic earthquakes within a 24-hour period.

The country's most active volcano has been rumbling with activity in recent weeks, sparking the evacuation of more than 15,000 people in Albay.

State volcanologists have hoisted Alert Level 3 indicating a 'high level of unrest' over Mayon Volcano. They said the unrest could last for months, and the high-risk zone around the volcano may be expanded should the eruption intensify.

Speaking to local media, Teresito Bacolcol, director of PHIVOLCS, said: 'Based on our experience, this activity may persist for a few months. If the eruption were violent, this would probably take a few days to weeks, but when it is slow like this, it would probably take several months.'

The Albay Public Safety and Emergency Management Office said around 15,241 people were staying in evacuation centres as of June 14.

The Albay local government has declared a state of calamity in the province last Friday, allowing authorities to tap emergency funds to support affected residents.

Mayon Volcano - a popular tourist attraction renowned for its 'perfect' conical shape - is the most active volcano in the Philippines. It last erupted in 2018, displacing around 40,000 residents.