MANILA (UPDATED) — The Mayon volcano could continue rumbling for months and force thousands of people in the central province of Albay to remain in evacuation centers, the Philippine Institute of Volcanology and Seismology (Phivolcs) said on Tuesday.

Lava or red-hot rocks continued to ooze slowly from Mayon's rumbling crater, Phivolcs Director Teresito Bacolcol said.

Phivolcs recorded one volcanic earthquake in the past 24 hours, down from 21 quakes logged the previous day. Sulfur dioxide emissions meanwhile went slightly up to 723 tons on Monday from Sunday's 642 tons, he said.

"Ang nakikita namin (what we are seeing) right now, it’s following the template of the 2014 eruption, which was a quiet eruption, effusive eruption," Bacolcol said.

"Based on our previous experiences, this activity may persist for a few months. Kapag naman violent yung eruption niya, this will probably just take a few days to weeks. Pero kapag ganitong mabagal, it will probably take several months," he told ABS-CBN's TeleRadyo.

(If it were a violent eruption, this will probably just take a few days to weeks. But if it's just slow like this, it will probably take several months.)

Five years ago, Mayon displaced tens of thousands of people after spewing millions of tonnes of ash, rocks and lava.

The 2018 eruption lasted from January to March, while the 2014 eruption took "almost the same number of months," Bacolcol noted.

On Thursday, a 5-step alert system for the volcano was raised from 2 to 3 after Mayon spewed ash and toxic gases.

Some 13,000 people have been moved to evacuation centers, most from farming villages at or near the foot of the volcano, authorities said Monday.

"Unless i-lower natin iyong alert level natin, we have no choice but yung mga taong nasa permanent danger zone will have to stay muna sa mga evacuation centers. In the first place, dapat walang tao d’yan sa permanent danger zone," Bacolcol said.

(Unless we lower our alert level, we have no choice but to make residents of the permanent danger zone stay in evacuation center. In the first place, no one should be living there.)

Watch more News on iWantTFC

SITUATION IN EVACUATION CENTERS

Residents from the danger zone are taking shelter at one community college, 13 schools, and 9 evacuation facilities, Albay Governor Edcel "Grex" Lagman said.

"The problem with some of these structures, hindi naman po talaga ‘to built for evacuation centers," he said in a separate TeleRadyo interview.

"We try to make do with what the law mandates na ang ibang mga DepEd schools, mga eskwelahan po ito, na ginagamit na evacuation center, so dapat i-factor in po natin yung pagsipsip po sa mga septic tanks, mga nag-o-overflow na na human waste," he said.

(Some of these structures were not built as evacuation centers. In some schools, we have to drain the septic tanks, the overflowing human waste.)

This is an "added strain" to the province's "measly" P30 million quick response fund, which studies project might only last for 15 to 20 days, the governor said.

The social welfare department has committed to give good packs to the province, while the Office of Civil Defense will deliver a water filtration system, he said.

Some evacuees have yet to receive drinking water from the authorities, said Larry Llenares, a barangay kagawad from Matnog in Daraga town.

"Kaya ngayon bumibili muna dyan sila ng parefill-an ng tubig. Tapos sa pagkain, kulang kasi ‘yung mga evacuation, pinapakain muna ng kapitan namin sa barangay namin sa Matnog," he told TeleRadyo.

(That's why they're buying water from a refilling station for now. Food is also running low in the evacuation center, our barangay captain in Matnog had to provide food.)

Lagman said he would meet with Albay mayors about the permanent relocation of residents out of the 6-kilometer danger zone around Mayon.

"Kailangan talaga dito mabago na iyong sistema sa Albay. Ayaw naming maging perennial problem ito na kada meron tayong mga ganitong pagbabanta ng pagsabog ng bulkang Mayon o ano mang calamity, evacuate na lang kami nang evacuate," Lagman said.

(We need to change the system in Albay. We don't want this to be a perennial problem, that every time Mayon threatens to erupt or there is a calamity, we just evacuating people.)

The local government also partnered with the labor department and the Technical Education And Skills Development Authority to offer livelihood programs and trainings to the evacuees, he said.

ENOUGH MEDICAL SUPPLIES

The Albay provincial health office also assured that it had sufficient supplies of medicine for evacuees should Mayon remain restive for months.

Provincial health officer Dr. Estella Zenit told ABS-CBN TeleRadyo that Gov. Lagman allocated P5 million for the health sector as part of the local government's quick response funds.

Zenit said Health Secretary Teodoro Herbosa also vowed to send additional medical supplies including medicines and face masks for use in evacuation centers.

"Nagre-reprogram na po ang province kung saan namin pwedeng kunin iyong ibang mga pangangailangan... kasi iyong [Provincial Social Welfare and Development Office] nangangailangan din sa health," she said.

(The province is now reprogramming its funds to look for other sources to help meet evacuees' needs. Our Provincial Social Welfare and Development Office is also in need of health-related supplies.)

Zenit also said evacuees usually ask for medicines to treat hypertension, diabetes, cough, and antibiotics.

• Albay local gov’t braces for Mayon Volcano alert level shift

TOURISTS STILL WELCOME

Watch more News on iWantTFC

Meanwhile, tourists are still welcome in Albay, tourism officer Dorothy Colle said.

Colle said they came up with safe viewing sites from which tourists can still view the majestic Mayon.

“Ang na-identify po naming viewing sites ay lampas doon sa 8-kilometer danger zone… Kino-consider din po namin kung saan ang ihip ng hangin pupunta. So, dito lang talaga sa may parteng southern side, southeastern side, diyan po kami ng mga destination kung saan pwede maitalagang viewing site,” she noted.

(Our identified viewing sites are beyond the 8-kilometer danger zone. As we are also considering wind direction, only areas in the southern and southeastern side of the volcano may be identified as viewing sites.)

She noted that about 500 visitors daily have been coming to the Cagsawa Ruins—a historical landmark about 9 kilometers from the base of the Mayon—since Alert Level 3 was raised there.

“Doon sa Cagsawa Ruins ho, na regular day, umaabot na mga 150 to 200 tourists per day. Ngayon nung umakyat na ng Alert Level 3, 500 per day na po ang mag tourist na pumupunta,” she said.

(About 150 to 200 tourists visit the Cagsawa Ruins on regular days. But since Alert Level 3 was raised over Mayon, about 500 tourists have visited the ruins daily.)

Mayon, about 330 kilometers southeast of Manila, is considered one of the most volatile of the country's 24 active volcanoes.

Earthquakes and volcanic activity are common in the Philippines due to its position on the Pacific "Ring of Fire" where tectonic plates collide.

The country's most powerful eruption in recent decades was Mount Pinatubo in 1991 that killed more than 800 people. That disaster produced an ash cloud that travelled thousands of kilometers.

Mayon lies in a region also hit by many of the roughly 20 typhoons or tropical storms to strike the Philippines each year.

The frequent weather disasters often kill people, ravage farms, and help to keep millions poor.

— With a report from Agence France-Presse