MANILA, April 8 -- Kanlaon Volcano's explosive eruption from 5:51 to 6:47 a.m. Tuesday was a result of gas pressure, the Philippine Institute of Volcanology and Seismology (Phivolcs) reported.

"Sulfur dioxide emissions have been low prior to the eruption. Volcanic earthquakes were also few, just 16 for the past 48 hours. This indicates pressure beneath (the volcano) because of gas," Phivolcs Director Teresito Bacolcol told the Philippine News Agency in an interview.

The pressure caused the volcano to erupt, he continued.

"An explosive eruption is a type of volcanic eruption that is highly violent and powerful, caused by the rapid release of gas and pressure from magma beneath the earth's surface," Bacolcol said.

Ash columns, gases and...