Philippine officials on Thursday raised the alert level for one of the country’s most active volcanoes after superheated streams of gas, debris and rocks cascaded down its upper slope in a condition they fear could lead to a hazardous eruption within days or weeks.

Villagers living within a 6 km radius of Mayon volcano’s crater were told to leave the long-designated permanent danger zone and move to safer grounds due to the danger of volcanic emissions, lava flows, rockfalls and other hazards, officials said.