Aircraft are prohibited from flying below 6,000 metres in the vicinity of the volcano, and should also remain alert to the presence of volcanic ash, which can disrupt flights.
Kanlaon Volcano, one of the 24 active volcanoes in the Southeast Asian nation, has had several eruptions in the past century – the most recent of which happened in April.
The Philippine Institute of Volcanology and Seismology (Phivolcs) raised Bulusan’s alert status from 0 to 1 on its five-level scale, signalling low-level volcanic unrest and warning of possible phreatic eruptions.
The volcano, situated on Halmahera Island, spewed a column of ash up to 2,000 metres into the sky. Thick white-to-grey clouds drifted south of the crater.
Mount Dukono, situated in Indonesia's eastern North Maluku province, erupted on November 26, prompting a warning for aviation, according to the country's Volcanology and Geological Disaster Mitigation Centre.
Indonesian authorities on May 16 raised the alert level for Mount Ibu, a volcano in North Maluku province, to the highest (Level 4) following a series of eruptions since last week.
More than 1,200 people were evacuated from their homes on January 19 as Mt. Egon volcano, in the eastern Flores island of Indonesia, spewed ashes and toxic gas into the air.
