Hundreds of families were ordered to leave their homes near a Philippines volcano on Saturday after an eruption sent ash and steam hundreds of metres into the sky.
Taal volcano, which sits in a lake south of Manila, exploded with a "short-lived" burst at 7.22am, the Philippine Institute of Volcanology and Seismology said.
It said further eruptions were possible, which could trigger dangerous, fast-moving volcanic flows of gas, ash and debris, as well as a tsunami.
The agency "strongly" recommended residents living in vulnerable communities around the lake be evacuated, as it raised the alert level from two to three.
The initial eruption was followed by "nearly continuous phreatomagmatic activity" that sent plumes stretching 1,500 metres into the air.
A phreatomagmatic eruption happens when molten rock comes into contact with underground or surface water, said Princess Cosalan, a scientist at the agency, likening it to pouring "water on a hot pan".
Ms Cosalan said the ash and steam emissions quietened after the initial burst, but the institute's on-site sensors continued to detect volcanic earthquakes and another eruption was "possible".
"There is magmatic intrusion at the Main Crater that may further drive succeeding eruptions," the agency warned.
Residents of five villages were ordered to leave their homes, regional civil defence spokesman Kelvin John Reyes said.
More than 12,000 people live in the settlements, the latest available official data shows.
Police have been stationed to stop people from entering high-risk areas.
Taal is one of the most active volcanoes in a nation hit periodically by eruptions and earthquakes due to its location on the Pacific "Ring of Fire" — a zone of intense seismic activity.
Access to the volcano island, which was once home to a community of thousands, has been prohibited since January 2020, when an eruption shot ash 15 kilometres high and spewed red-hot lava, crushing scores of homes, killing livestock and sending tens of thousands into shelters.
Last July, the seismological agency raised the alert level to three after Taal burst to life again.
It belched sulphur dioxide for several days, creating a thick haze over the capital and surrounding provinces.
The alert level was lowered back to two before Saturday's eruption.