A volcano eruption in the Philippines turned the sky dark gray with ash.

Footage shows the apocalyptic scene as Bulusan volcano belched out thick clouds of steam and ash in Sorsogon province on June 5. The ash particles later covered houses in nearby villages and triggered evacuations.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said the eruption started at 10:37 am local time and lasted for some 17 minutes as the volcano churned out clouds of vapour.

Houses in villages near the volcano's vicinity were covered in ash. Authorities said at least 1,500 families in the province were affected and have moved into evacuation centres.

The Sorsogon Provincial Information Office warned residents against travelling in the meantime as the fine particles reduced road visibility and posed harm to locals with respiratory diseases.

Phivolcs Director Renato Solidum in an interview with local media said: 'It may or may not explode soon but in the past events or eruption episodes of Bulusan, the interval of eruption can happen between days, weeks or months.'

The institute has raised Alert Level 1 over Bulusan volcano, indicating 'low levels of volcanic unrest.'

Phreatic eruptions are explosions driven by steam that forms when underground water is heated by magma, lava, or hot rocks, the United States Geological Survey glossary said.