Once the alert status was raised on Thursday on a restive volcano that spewed a one-kilometre (0.62 mile) high plume of gas and steam, Philippines authorities started evacuating thousands of people.

The alert for the Taal volcano, about 70 km south of central Manila, moved to level 3 from level 2 on the 5-level scale, which the seismology and volcanology agency said meant a “magmatic intrusion” at the main crater “could further drive succeeding eruptions”.

Taal is one of the world’s smallest active volcanoes. Despite standing at only 311 meters, it can be deadly and an eruption in 1911 killed more than 1,300 people.

In January last year, Taal shot a column of ash and steam as high as 15 km into the sky, which forced more than 100,000 people to abandon their homes, widespread flight cancellations and heavy ash falls in Manila.

Water in Taal’s crater boiled before and after its eruption, a video posted on the Facebook page of the seismology agency showed.