MANILA Massive eruptions shook Mayon Volcano in the central Philippines on Sunday, sending more than 11,000 people fleeing from superheated rocks shooting up from its crater, officials said.

With a sound like extended claps of thunder, huge geysers of rocks, lava and gray ash spurted from the crater rim at 12:15 p.m. (0415 GMT) and then again at 3:03 p.m. (0703 GMT), residents and reporters on the scene said.

Volcanologists said the material shot up to a height of up to 15 kilometers (9.3 miles) from the apex of the 2,467-meter (8,141-feet) mountain.

"The skies went dark in Malilipot and Santo Domingo," two towns near the northern slopes of Mayon, provincial social welfare officer Jim Rebustillo told AFP. "The volcano roared like thunder."

He was speaking from the provincial capital Legaspi, about 325 kilometers (200 miles) southeast of Manila.

Volcanic ash rained down on the towns of Camalig, Guinobatan and Ligao to the south, while lava flowed toward a now-abandoned village on the outskirts of Legaspi, near Mayon's southeast flank, Rebustillo said.

The civil defense office here said military trucks were helping the police and local officials evacuate residents in threatened areas.

Local television showed sleepless residents, many of them women carrying babies, clambering aboard flatbed trucks before dawn as molten lava fragments created a fiery fountain above the crater.

Manila's Volcanology and Seismology Institute raised the highest of a five-stage volcano alert shortly after noon on Sunday, officials told AFP.