Local authorities have temporarily banned all climbing activities on Mount Slamet in Central Java due to an increase in volcanic activity.
The volcano, which spans five regencies in the province, namely Tegal, Brebes, Pemalang, Purbalingga and Banyumas, reportedly began to rumble and emit lava on Wednesday night.
Sudrajat, an official with the Mt. Slamet observation post in Pulosari Pemalang, said the volcano had been increasingly active since Tuesday.
"Between Wednesday night and Thursday afternoon, Mt. Slamet emitted fireballs from its crater to a height of between 50 and 300 meters," Sudrajat said on Thursday as quoted by tribunnews.com.
He added that the 3,432 meter volcano had been placed on a waspada (alert) footing for the past week, causing concern among locals living nearby.
Tremors were recorded 21 times on Wednesday and emitted volcanic ash 419 times.
"Due to this current situation, officials are prohibited from conducting any activity within a 2-kilometer radius of Mt. Slamet," Sudrajat added.
He also said a strict prohibition was in place to prevent anyone from scaling the volcano to celebrate Independence Day on Aug. 17.