The number of Filipinos fleeing from the erupting Mayon Volcano to safe zones has swelled to nearly 90,000, officials said Monday, worsening a sanitation crisis in the already stretched relief camps.
President Rodrigo Duterte flew to the central city of Legazpi on Monday to assess the disaster zone, some two weeks after the country's most active volcano began belching spectacular but potentially lethal ash columns, lava and rocks.
Authorities have thrown a nine kilometer (5.6 mile) no-go zone around the mountain with the vast majority of those living in its shadow now safely outside that radius.
But sanitary conditions in the safe-zones are far from ideal.
Al Francis Bichara, the governor of Albay province, said authorities expect the evacuees will need to stay at the camps for at least a month.
But he warned limited local government resources were being stretched, citing the lack of toilets at the shelters, where he said an average of 200 people now took turns using one.
"We lack 1,222 toilets," he said, adding the ideal was one toilet for every 50 evacuee (1,800 total).
After being briefed by officials Duterte said he was worried about the lack of toilets.
"One worry really is the sanitation," he told the officials, adding his government would try to send as many portable cabins as possible in the coming days.
Officials said they were confident the no-go zone radius was large enough to keep people safe from even a large explosive eruption.
"Even if that happens we think the people are already safe," state volcanology institute chief Renato Solidum said.
He stressed the eruption was not over despite a relatively quiet weekend, estimating some "50 million cubic meters" more debris had the potential to be ejected from the crater in the coming days and weeks.
If cooling lava blocks the crater gas pressure would build up and cause the magma inside to explode, producing eruption columns far taller than the five-kilometers-tall clouds seen in previous days, he said.
Officials have also told AFP farmers are also going back to the danger zone to tend to their crops and livestock, putting them within range of white-hot volcanic debris shooting down Mayon's flanks at great speed.
Solidum said local authorities were also making sure loose volcanic debris deposited on Mayon's flanks would not threaten lives and properties should they be dislodged by heavy rain and turn into mudslides.
The 2,460-meter (8,070-foot) Mayon, a perfect cone rising 330 kilometers southeast of Manila, is the country's most active volcano -- now on its 52nd eruption in four centuries.
It killed 1,200 people when it buried the town of Cagsawa in 1814.