Four volcanoes in the country —Taal, Kanlaon, Mayon, Bulusan —remain under Alert 1, the Philippine Institute of Volcanology and Seismology (Phivolcs) said on Monday. Kanlaon Volcano in Negros Island, in a state of unrest and in an abnormal condition following a minor steam explosion last week, was recorded having 11 volcanic earthquakes since Sunday. Weak to moderate emission of white steam plumes that rose up to 50-meter high above the summit crater has been monitored.