A volcano in eastern Indonesia erupted on Sunday, sending a column of ash 4,000 metres into the sky and prompting thousands of people to flee. About 2,800 people fled from at least 28 villages on the slopes of Mount Ili Lewotolok on Lembata island, East Nusa Tenggara province, as the volcano began erupting, Disaster Mitigation Agency spokesman Raditya Jati said. There were no reports of deaths or injuries from the eruption. The Transportation Ministry said a flight warning was issued after the eruption and a local airport was closed as ash rained down on many parts of the island. Mount Ili Lewotolok has been erupting off and on since October 2017. The Volcanology and Geological Hazard Mitigation Centre raised the volcano's alert level to the second-highest stage on Sunday after sensors picked up increased activity. The 5,423-metre mountain is one of three currently erupting in Indonesia, along with Merapi on Java island and Sinabung on Sumatra island. They are among more than 120 active volcanoes in Indonesia, which is prone to seismic upheaval owing to its location on the Pacific "Ring of Fire", an arc of volcanoes and fault lines around the Pacific Ocean. After the eruption, the Disaster Mitigation Agency advised villagers and climbers to stay four kilometres from the crater and be aware of the peril of lava.