LEGAZPI CITY. Relief supplies began arriving Tuesday as thousands of Philippine villagers braced for a lengthy stay in overcrowded evacuation centers as restive Mayon Volcano held its fire.

Officials say they have enough resources for one week, but they fear the villagers may have to stay in evacuation centers for up to two months due to Mayon's recent instability.

In Metro Manila, Office of Civil Defense (OCD) deputy administrator and spokesman Anthony Golez said three mobile hospitals and 200 doctors from the Armed Forces Reserve Command will be dispatched to Albay province to serve the needs of the more than 40,000 people evacuated from a danger zone around restive Mayon Volcano, an official said Tuesday.

The three mobile hospitals, which are worth eight million dollars, were donated by the United States and are similar to those used by the Americans in Iraq.

Truckloads of food and clothing from the Philippine National Red Cross, charity group World Vision, local civic groups like the Rotary Club and food and beverage giant San Miguel Corporation, have started to arrive for the 44,000 people forced to flee their homes.

"There are plenty of non-government organizations and companies that are willing to support us in relief items and food," said Legaspi City's disaster coordinator Pecos Intia.

The mobile hospitals, each of which has a 50-bed capacity and is equipped with an operating room and generators, will be transported to the Mayon area within the week, Golez said.

They were donated in late 2004, after floods and landslides killed scores of people in Quezon and other provinces, but "were never used in…since they arrived when we were in the rehabilitation phase," he added.

The doctors, on the other hand, will be deployed to the 30 evacuation centers in Albay that, Golez said, authorities are working to decongest on orders of President Gloria Macapagal-Arroyo amid worries of the crowded conditions will prove conducive to disease outbreaks.

Golez said officials are considering opening more schools to evacuees.

During a visit to Albay, Arroyo also ordered the speeded up construction of pre-fabricated shelters and tents.

Mayon began spewing lava, ash and gas August 7, leading volcanologists to warn of an imminent eruption. The government ordered mandatory evacuations the same day.

A six to eight-kilometer (four to five-mile) 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.

The evacuated villagers sleep on 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 day after day."

But she was especially grateful for donations of pork because they added variety to meals.

While the volcano has continued to simmer and send occasional bursts of deadly volcanic ash and gas into the surrounding area, it has yet to explode.

But the Philippine Institute of Volcanology and Seismology (Phivolcs) said that the continued ash explosions, volcanic quakes and gas emissions showed the volcano was still in a high state of unrest.

Scientists warn that an eruption is still likely and that it is too dangerous to let people return home.

Provincial Social Welfare Officer Yolanda Guanzon said that in view of previous eruptions, the villagers might have to stay at evacuation centers for as long as two months.

To stretch out the relief goods, the city and provincial government, augmented by charity donations, will handle the initial upkeep of the evacuation centers. The national government will step in next month, Guanzon said.