"Some U.S. military personnel who have been in the Philippines for the joint exercises will remain for a short period to transport and help set up, in conjunction with their Filipino counterparts, the additional shelters for Mayon evacuees," U.S. Ambassador Thomas Hubbard said in a statement.
The Mayon volcano in Albay province, which began erupting on February 24, was calm for a third day on Saturday.
About 68,000 people or 14,000 families have been brought to 52 evacuation centres, most of them public schools in the towns around the volcano, 330 km (190 miles) southeast of Manila.
As many as 65 people crammed classrooms typically big enough for 35 pupils.
Philippine Army Colonel Dante Bonifacio said 20 U.S. soldiers would be joined by 100 of their Filipino counterparts in the effort, which comes days after the armed forces of both countries ended two weeks of military exercises.
At least 56 tents would be built on Sunday in a 22-hectare (54-acre) area in Daraga town, 20 km (12 miles) from the volcano, whose eruptions over the past 10 days have blanketed eight nearby farming towns in ash.
The tents, part of a special $418,000 U.S. relief package, were to be flown in on Sunday on a U.S. C-130 transport plane, along with bottles of water, and water purifiers.
"We respond to the relief operations by bringing tents and water purification. We hope to help the dislocated families to ease their burden. We will deliver water and put up tent cities," said U.S. Navy officer Bob Harward.
The United States will also fly in sheets, portable toilets, watertanks and portable jerry-cans for the evacuees.
Disaster relief officials have said diarrhoea was the most common complaint in the evacuation centres, followed by fevers, coughs and colds.
FOOD IN SHORT SUPPLY, FARMERS FACE RUIN
Food is also in tight supply for the evacuees, many of them farmers, and their livestock.
Agriculture is the main source of livelihood of 80 percent of families living in towns around the 2,460-metre (8,000-ft) volcano but many of their homes and farms have been covered by ash. The farmers rely on cows and carabao (water buffalo) to till their land because tractors are too expensive.
Cesar Marcellana, a 39-year-old farmer from Daraga town, at the foot of the volcano, said he had to sell his water buffalo to buy food for his wife and four young children.
"We only get one kilo or rice, one can of sardines and one pack of instant noodles a day. It doesn't matter how big or small your family is. We have to dig from our own pockets so we do not get hungry," he said.
"So I sold my carabao. If this situation goes on, I might even end up selling my chickens, or eating them."
Farmer Mariano Villanueva said he wished livestock could also be sheltered from the wrath of the volcano.
"Much as we would like to bring the animals here, we could not, because this place is crowded. They only let us bring chickens," Villanueva told Reuters at an evacuation centre in Guinobatan town.
Villanueva said he and most of his neighbours were forced to abandon their livestock in the fields when disaster relief officials took them to evacuation centres after the eruptions started.
The farmers have since been going in and out of the six-km (3.7-mile) danger zone around the volcano every day to bring food, mainly banana leaves, to the animals.
"It's a good thing that it has been raining since Friday, because the rainfall washes away the ash from the grasses in the field, so our carabaos can eat again," Villanueva said.
- Reuters - Thomson Reuters Foundation
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