MANILA: Lava and broad columns of ash illuminated by lightning spewed from a volcano south of the Philippine capital on Monday (Jan 13), grounding hundreds of flights as authorities warned of a possible "explosive eruption".
Taal volcano, a popular tourist attraction set in the centre of a picturesque lake, spewed ash, rumbled with earthquakes and exploded with lightning above its crest.
More than 16,000 people were evacuated from the volcanic island and the area immediately around it as dozens of tremors set residents on edge.
"You could not sleep anymore, because every time you closed your eyes the house would shake," restaurant owner Lia Monteverde told AFP, saying the quakes came minutes apart.
"All of us didn't sleep at all. We just prepared to leave."
Flight operations at Manila's international airport partially resumed, authorities said, after at least 240 flights were delayed or cancelled on Sunday, snarling plans for tens of thousands of people travelling through the Ninoy Aquino International Airport.
One flight that did land carried President Rodrigo Duterte, who was coming back from his home city of Davao in the southern Philippines. He had been unable to fly on Sunday because visibility was so low.
Singapore Airlines had announced that several flights between Singapore and Manila on Sunday and Monday are rescheduled to a later time.
AirAsia also cancelled domestic and international flights that connect to cities including Bangkok, Shanghai, Taipei, Osaka and Seoul.
Taal, one of the world's smallest active volcanoes, sits in the middle of a lake about 70km south of the centre of the capital, Manila.
The eruption began with an explosion of superheated steam and rock, but by early Monday "fountains" of lava had been spotted on Taal, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.
Authorities raised the volcano alert level to its second-highest on Sunday, saying an "explosive eruption" could happen in "hours to days".
They warned that an eruption could send a tsunami surging across the lake.
"Taal is a very small volcano, but a dangerous volcano," Renato Solidum, head of The Philippine Institute of Volcanology and Seismology (Phivolcs), told Reuters. "It is unique because it is a volcano within a volcano."
The Philippines lies on the Ring of Fire, a belt of volcanoes circling the Pacific Ocean that is also prone to earthquakes.
One of the most active volcanoes in the Philippines, Taal has erupted more than 30 times in the past five centuries, most recently in 1977. An eruption in 1911 killed 1,500 people and one in 1754 lasted for a few months.
"That is the worst case scenario," Solidum said.
Residents woke up on Monday morning to discover thick mud on the ground made up of ashes mixed with rainwater.
President Duterte's office ordered the suspension of government work in the capital and of all school classes in Manila and other areas affected by the ash. A statement advised private companies to follow suit.
In Manila, long queues formed in shops selling face masks as health officials warned of possible breathing problems for people with respiratory ailments and urged the public to stay indoors and use dust masks when going out.
"When I went to my car to bring my groceries, I saw it was covered in ash. So I hurriedly went back inside to buy a mask from a drugstore but they had run out," said Angel Bautista, 41, a resident of Paranaque city, south of the capital.
"Ash has already reached Manila ... it is dangerous to people if they inhale it," Solidum told AFP.
Apart from the ash, some particles up to 6.4cm in diameter, larger than a golf ball, had reportedly fallen in areas around the lake, Phivolcs said early Monday.
By that time 52 volcanic earthquakes had occurred, it said.
"Such intense seismic activity probably signifies continuous magma intrusion beneath the Taal edifice, which may lead to further eruptive activity," Phivolcs said.
Social media users posted images of cars and porches coated in fine, dark-coloured grit and commented on where to buy dust masks.
Taal's ash plume was clearly visible from the city of Tagaytay, a well-frequented viewing spot for the volcano.
"We were having lunch when we heard rumbling. We saw the volcano erupting. It rained and some small pebbles fell to the ground," Jon Patrick Yen, a restaurant customer in Tagaytay, told Reuters.
"I did not expect to see such spectacle. We just went by to eat."
Two years ago, Mount Mayon displaced tens of thousands of people after spewing millions of tonnes of ash, rocks and lava in the central Bicol region.
The most powerful explosion in recent years was the 1991 eruption of Mount Pinatubo, about 100km northwest of Manila, which killed more than 800 people.
It spewed out an ash cloud that travelled thousands of kilometres in a matter of days and was blamed for damaging nearly two dozen aircraft.