Warnings of ‘Volcanic Tsunami’ After Eruption in Philippines

MANILA — A dramatic explosion of the Philippines’ second-most-active volcano on Sunday prompted warnings of a possible “volcanic tsunami” as villagers were evacuated and nearby communities were advised to take precautions against any lake water surges.

The explosion, which sent a plume of ash half a mile into the air, came months after the volcano — Taal, about 40 miles south of Manila — began exhibiting a state of unrest. Tremors were felt on the volcano’s island and in villages around the nearby town of Agoncillo in Batangas Province, and booming noises from the volcano raised fears among residents.

“The earthquakes were strong, and it felt like there was a monster coming out” as in the movies, said Cookie Siscar, who had left the area and was relaying a report from her husband, Emer, a poultry farmer, who was in their home in Batangas, which overlooks the volcano island.

The Philippine Institute of Volcanology and Seismology raised its alert level for Taal Volcano to four out of five, indicating that a “hazardous eruption” was imminent.

The institute warned that the eruption could cause a “volcanic tsunami” and advised nearby communities to take precautions against possible surges from the lake that surrounds the volcano. About 6,000 people live on the island, and boats took residents to safety in Batangas early on Sunday.

Tens of thousands of people were ordered evacuated from the surrounding area, The Associated Press reported, but there were no immediate reports of injuries or damage. Manila’s international airport also said on Twitter that flights to and from it were suspended because of the eruption. Volcanic ash was seen “in the vicinity of the airport” and nearby air routes, the Civil Aviation Authority of the Philippines said.

The volcano island has been showing signs of activity since last March, and about three dozen eruptions have been recorded in recent history. Sitting on a lake that partly fills a caldera formed thousands of years ago, it is a popular attraction for tourists, who view it from a ridge in Cavite Province to the north.

Salvador Panelo, a spokesman for President Rodrigo Duterte, said the government was “closely monitoring the situation of Taal Volcano.”

“Concerned agencies of the national government are now working closely with the provincial government of Batangas to ensure the safety of the residents, including their evacuation,” Mr. Panelo said. “We advise the public to continue to remain vigilant.”

Rea Torres, who is from the town of Dita in Batangas, said that when she went to check on the family residence, she felt tremors twice: “I felt as if the whole floor moved.”

“It is very scary,” she said, describing “ominous clouds above us” and thunder and lightning.

Last January, an eruption at the most active volcano in the island nation — the Mayon, in Albay Province, about 200 miles east of the Taal — prompted an alert level of four as it generated up to 1,600 feet of lava fountains and ash fell on two nearby villages.