A volcano near the capital of the Philippines has spewed ash and lava into the sky, possibly portending a bigger and more dangerous eruption.

Tens of thousands of people have fled villages darkened and blanketed by heavy ash after the activity at the Taal volcano in Batangas province, south of Manila.

Government work was suspended and schools were closed in a number of towns and cities, including Manila, because of the health risks over the ash.

Hundreds of flights were cancelled or delayed, affecting tens of thousands of passengers.

The continuous activity at Taal and several new fissures cracking the ground nearby likely means magma is rising and may lead to further eruptive activity, the Philippine Institute of Volcanology and Seismology said.

The volcano was spurting fountains of red-hot lava half a mile into the sky, with the massive column of ash and volcanic debris occasionally lighting up with streaks of lightning.

The alert level since the eruption began Sunday has been 4, indicating a hazardous eruption is possible in hours to days.

Philippines Volcano
Residents clear their roofs covered with volcanic ash at Laurel, Batangas province (AP)

Level 5, the highest, means such an eruption is under way.

About 50 volcanic earthquakes were detected over eight hours on Tuesday, indicating rising magma, the institute said. It also warned heavy and prolonged ash fall was possible in nearby villages.

The picturesque volcano in the middle of a lake rumbled to life on Sunday in a powerful explosion that blasted a nine-mile column of ash, steam and rock into the sky.

Clouds of volcanic ash blowing over Manila, 40 miles to the north, closed the country’s main airport on Sunday and part of Monday until the ash fall eased.

More than 500 international and domestic flights were cancelled or delayed due to the overnight airport closure, affecting about 80,000 passengers.

The disaster response agency counted more than 40,000 evacuees in Batangas and nearby Cavite provinces who took shelter in nearly 200 evacuation centers. Officials expect that number to swell.

President Rodrigo Duterte plans to visit volcano-devastated areas in Batangas, which has been declared a calamity zone for faster disbursement of emergency funds.