LEGAZPI, Philippines – A volcano in the Philippines spewed ash Wednesday after the amount of gas coming from the crater dropped suddenly, worrying experts that something had blocked the flow of magma and could cause a bigger eruption.
A drop in sulfur dioxide emissions in the 8,077-foot Mayon volcano could indicate that pressure is building up for an explosive eruption, said Renato Solidum, director of the Philippine Institute of Volcanology and Seismology.
"Either something is stuck there and there will be an explosion, or the magma coming out has less gas," he said. "So it still means we still need to be cautious."
On Monday, the institute raised its alert for Mayon to Level 4 — the second highest level — after six explosions sent ash columns up to a half-mile high. About 32,700 villagers have since been evacuated near the volcano in Albay province, about 210 miles southeast of Manila on Luzon island.
Officials have declared a danger zone of five miles on the volcano's southern side.
After Wednesday's eruption, which was obscured by clouds, the volcanology and seismology institute reported that Mayon was undergoing "a period of high unrest, which has a high probability of evolving into a hazardous explosive eruption."
Despite such warnings, some residents have refused to leave farming villages close to the volcano.
Soldiers on Wednesday ordered two tomato farmers who were trying to retrieve a water buffalo less than a half-mile from a smoldering lava pile in Mabinit village to evacuate.
"I will give you two a choice, you can either go down by 11 a.m. or we will put you in our trucks," Maj. Virgilio Noora told the farmers, who said they would comply.
Farmer Jun Mena said he was scared to be so close to the rumbling volcano but said he had no choice. "We have to tend to our crops," he said. "We're gambling our lives because it's our source of livelihood."
Officials have been hoping that Mayon, which has erupted at least 47 times in the last 400 years, would go off quietly. Mayon is one of the Philippines' 22 active volcanos and its most violent eruption, in 1814, killed more than 1,200 people and buried a town in mud.
Its recent activity began July 14 in a "quiet" eruption characterized by lava trickling down Mayon's southeastern slopes.