Lava flowed a mile down the side of one of the most active volcanos in the Philippines today, as scientists met to decide if it was about to erupt.
The Philippine Institute of Volcanology and Seismology was discussing whether to raise its public alert about a possible eruption from the current level of three on a five-point scale.
Level three means an eruption could occur within weeks. Level four indicates that an eruption is expected within days, and level five means a hazardous eruption is in progress.
Although no explosions have been recorded on the Mayon volcano since it became active in January, a sudden outburst of gas-filled lava could still be coming, the institute said.
Seismographs recorded 265 tremors during a 24-hour period ending at 8am (0100 Irish time) today, up from an average 203 last week.
Ed Laguerta, a resident volcanologist in Legazpi City near Mayon, said a slow-moving river of lava, including red-hot rocks and boulders, was flowing through a gully on the southeastern slope of the volcano today.
He said clouds hanging over the volcano were reflecting the bright glow of rising lava inside it.
Mayon, a cone-shaped mountain towering above farming communities in the Bicol region, 200 miles southeast of Manila, is a tourist attraction in the Philippines. Its most violent eruption occurred in 1814, killing more than 1,200 people and burying an entire town in volcanic mud.