(CNN) — A volcano on the main island of Indonesia has sent plumes of smoke and ash high into the air, while tens of thousands have gone to shelters for safety, the Antara state news agency reported Thursday.
The government raised its eruption alert to its highest level overnight, and authorities have ordered an evacuation of all residents in a 10-kilometer (6.2 miles) radius of Mount Kelud in eastern Java.
Flights at area airports — two in East Java, two in Central Java — were canceled because of the ash.
According to National Disaster Mitigation Agency spokesman Sutopo Purwo Nugroho, lightening was seen striking the volcano’s peak as it spewed debris.
The nation’s volcanology agency said other, smaller eruptions could happen, which is why authorities are urging people to stay outside the 10-kilometer radius, the spokesman said.
Pictures from the scene show large black plumes rising over Mount Kelud, raining pebbles and ash on the surrounding area.
The military has been called in to help evacuate the area, and 66,000 people are moving to nearby shelters.
Mount Kelud last erupted in 2007, but it has recently ramped up activity in the past 10 days.
In 1990, an eruption killed more than 30 people and injured hundreds.
Indonesia is part of the vast “Pacific Ring of Fire,” an area of colliding continental plates where powerful earthquakes and volcanic eruptions often occur.
By Brian Walker
CNN’s Kathy Quiano contributed to this report.