The Philippines' restive Mount Bulusan spewed ash and small rocks in a new explosion Sunday, prompting army troops and authorities to evacuate nearly 100 residents from one ash-hit village because of health concerns, officials said.

With the new ash explosion, Bulusan's eighth since March, Filipino scientists said they would assess anew the possibility of a major eruption.

Renato Solidum, director of the Philippine Institute of Seismology and Volcanology, said the explosion belched ash up to 1.2 miles into the sky. Scientists said they needed to gather more details and possibly conduct a second aerial survey of Bulusan's summit in a week before they can assess the prospects of a major eruption.

A number of mild tremors accompanied the blast of ash, officials said.

Bulusan's recent ash and gas ejections indicate molten rocks called magma may be moving up within the volcano but it remains to be seen whether it would lead to a major eruption, Solidum said.

"It's possible, that's why we're monitoring," he told The Associated Press by telephone.

Wind was blowing ash from the mid-afternoon explosion to the northwest toward the farming towns of Casiguran and Juban, which have been grappling with volcanic ash and fears of a major eruption since the 5,149-foot volcano came back to life in March.

Its last major eruption was in 1994.

"It was a loud blast, there are small rocks and it's getting dark," Casiguran Mayor Edwin Hamor said by mobile phone as he rushed by car to a village in the path of falling ash.

In Juban, army and government trucks evacuated nearly 100 children and adults from the village of Puting Sapa to a school building away from the volcano due to health concerns, said Noel Pura, a local disaster-response official.

Puting Sapa was hit by thick ash and villagers there asked officials to move them to a temporary evacuation site because of the strong sulfuric stench. Male villagers were left behind to guard houses and the evacuated residents could return home Monday, Pura said.

Separately, about 40 farming families that had refused to leave their homes within a 2.5-mile radius of the crater that has been designated a permanent danger zone have agreed to move to a temporary relocation site or to houses of relatives starting Monday, Hamor said.

President Gloria Macapagal Arroyo inspected Casiguran and other towns Saturday and ordered local officials to ensure villagers are moved away from dangerous areas due to the possibility of a major eruption.

Bulusan is about 240 miles southeast of Manila.

The Philippines, which has about 22 active volcanoes, is in the Pacific "Ring of Fire," where volcanic activity and earthquakes are common.