Manila, April 30 -- An increase in the sulfur dioxide (S02) emission reaching 2,707 tons was observed in Kanlaon Volcano on Tuesday, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.

The volcano has been emitting an average of 1,300 tons per day this year, while a high average of 3,098 tons was recorded last January 19.

In an advisory, Phivolcs noted that although Kanlaon's volcanic earthquake activity has remained at a baseline average of three per day, increased seismicity has been recorded several times this year.

"The volcano is continuously releasing sulfur dioxide. Although this volume is quite significant since Kanlaon normally spews out very minimal SO2 of about 50 tons per day, this does not mean this wil...