Brief breaks in the clouds covering Mayon indicated fresh deposits in some gullies to the east and northeast of the summit, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.
"More explosions from the crater are expected, and these shall likely generate pyroclastic flows," the institute said in a statement, referring to the gas, ash and debris flows.
Lava flowing down Mayon has already destroyed wide swaths of farmland and permanently altered the terrain near two villages, volcanologist Ed Laguerta said.
Some 50 hectares of farmland and plantations have been destroyed by the lava that has trickled at least 6.7 kilometers since July 14, covering once-fertile agricultural land with molten rock and debris 10 to 15 meters deep, Laguerta said.
Overnight, instruments recorded four mild ash explosions, 24 volcanic earthquakes and 330 tremors from lava fragments tumbling from the crater and upper slopes.
"The explosions, volcanic earthquakes, lava extrusion and high rates of degassing indicate a continuing high unrest at Mayon," the institute’s bulletin said.
Scientists have said the 2,462-meter volcano may be gearing up for an explosive eruption.
Laguerta said the volcano did not culminate its eruption episode in the past without either a minor or major explosion taking place.
"If we will base the prediction on the history of Mt. Mayon, it is a very high possibility that the volcano will proceed to an explosive eruption. How soon is actually the question," Laguerta told The STAR.
Mayon started to spew ash and sulfuric dioxide last month. Last week, the institute raised the alert to Level 4 — the second highest of a five-step warning system — on fears of a possible "hazardous" eruption within days.
Laguerta said since the alert was raised on Aug. 7, the volcano has had 35 ash explosions and has maintained an almost constant level of restiveness. But the expected explosive eruption has yet to take place.
"Maybe this week, we will re-assess the situation if this will not blow up," he said, adding volcanologists may recommend shrinking the evacuation area.
A six- to eight-kilometer danger zone has been set up around the volcano and residents within the zone have been forced to seek refuge in 28 overcrowded evacuation centers.
Nearly 44,000 residents have been evacuated from 32 villages, officials said.
Three modern hospital tents, donated by the US in 2004 when Quezon province was struck by killer landslides, would be sent to Albay to serve the medical needs of evacuees.
Dr. Anthony Golez, spokesman for the Office of Civil Defense, said yesterday that the tents, which are similar to those being used by US forces in Iraq, are airconditioned and equipped with hospital beds, operating tables, generators and water tanks.
The tents, which cost around $8 million, could accommodate around 50 patients each at a given time.
Golez said they are also planning to use portable tents prepared by the Department of Social Welfare and Development, the Philippine National Red Cross and the Department of Education.
Aside from the hospital tents, some 200 doctors from the Armed Forces of the Philippines Reserve Command (AFPRESCOM) would also be deployed to the Mayon area to provide medical services to the evacuees.
Meanwhile, education officials in the region have ordered the holding of classes right at the temporary shelters.
Epifanio Buela, schools division superintendent for Albay, said this is to ensure that the calamity would not disrupt the learning of the elementary and high school students.
"We adopted the scheme because we believe that classes must go on with or without a calamity," he said.
He admitted though that students and teachers are not very comfortable with the setup since they have to make do with the facilities the evacuation center can offer.
Over 30 percent of those moved to evacuation sites are elementary and high school students whose schools are also anticipated to be affected by a hazardous eruption.
Relief supplies began arriving yesterday as thousands brace for a lengthy stay in overcrowded centers.
Truckloads of food and clothing from the Red Cross, the charity group World Vision, local civic groups like the Rotary Club and food and beverage giant San Miguel Corp. have started to arrive.
"There are plenty of non-government organizations and companies that are willing to support us in relief items and food," said Legazpi City’s disaster coordinator Pecos Intia.
The evacuated villagers, however, sleep in cold cement floors in converted schools, with some 50 people crowded into each classroom. They receive adequate but monotonous rations of rice, instant noodles and canned goods.
Flor Agao, 41, a housewife living in an evacuation center, said: "It would be ungrateful for us to say we are getting tired of eating the same thing everyday."
But she said, they will be grateful for variety. — AP, AFP, Cet Dematera, James Mananghaya