MANILA, Philippines (AP) — A restive Philippine volcano briefly erupted Tuesday on a central island, sending a 4-kilometer (2.4-mile) plume of ash and debris into the sky and forcing authorities to suspend school classes in four villages due to ashfall, officials said.

There were no reports of injuries or damage from Mount Kanlaon’s latest eruption after dawn that lasted more than an hour and scattered ash in at least four farming villages southwest of the volcano on Negros island, the Philippine Institute of Volcanology and Seismology said.

Kanlaon last erupted in December, prompting the evacuation of thousands of villagers, many of whom remained in emergency shelters on Tuesday as the volcano continued showing signs of restiveness, the Office of Civil Defense said.

Philippine chief volcanologist Teresito Bacolcol told The Associated Press there were no other key signs of restiveness, like a spike in volcanic earthquakes, that would prompt the alert on Kanlaon to be raised from the current level 3, which means a “high level of volcanic unrest.” The highest alert, level 5, means a “hazardous eruption is in progress.”

“The possibility of a bigger eruption is always there,” Bacolcol said, urging people to remain vigilant and stay away from a 6-kilometer (3.7-mile) danger zone around Kanlaon.