JAKARTA, Nov. 27 (Xinhua) -- Indonesia has raised alert for Mount Agung volcano to the highest level 4, disaster management sources said on Monday.
Authorities shut the main airport in Bali island after powerful eruptions on Sunday, spokesman of national disaster management agency Sutopo Purwo Nugroho told Xinhua.
The level of eruption rose to magmatic stage from phreatic stage with a gigantic fires displayed during the night and its rumbling reaching 12 km from the crater, the spokesman said.
"In anticipating the risks the volcanologists have raised the alert status to the highest level," he said through text message.
Mount Agung alert status was downgraded to the second highest on Oct. 19 after the volcanologists upgraded it to the highest on Sept. 22.
The volcano erupted on Saturday with the highest height of ash spewed by up to 4 km to the sky.
Sutopo said that all villagers in the no-go zone must immediately be evacuated.
Ngurah Rai international airport has been closed since 07:00 a.m. local time Monday (2300 GMT Sunday) and evaluation will be undertaken for every 6 hours by flight authorities, secretary of air transport of the transport ministry Pramintohadi Sukarno said on Monday.
The closure was conducted after the meteorology and geophysics agency said that the airspace around the airport is within the volcano ash spread, he said.
"Ngurah Rai airport has been impacted and it is in the area of volcanic ash spread of Mount Agung. Therefore the directorate general of air transport decides to close the airport for flight safety reason," said Pramintohadi.
The center of volcanology and geological hazard mitigation (PVMBG) has also raised volcano observatory notice for aviation or VONA to the highest red level.
Over 200,000 foreign visitors visit Bali island every month, according to the national statistics bureau.
Mount Agung last erupted in 1963, killing 1,100 people. It is one of Indonesia's 129 active volcanoes.