Mount Bromo volcano on Indonesia’s Java Island spewed ash into the air from a series of minor eruptions on Sunday, prompting scientists to warn of possible danger to airline flights.

Gede Suantika, head of the Centre of Vulcanology and Geological Mitigation, said the ash had reached the Abdurahman Saleh Airport nearby city of Malang.

Mount Bromo’s status was upgraded to top alert on Friday and placed off-limits to visitors, but no evacuation order was issued for residents living nearby.

The 2,329-meter peak, about 750 kilometres east of Jakarta, is a popular tourist destination. Two tourists were killed when the volcano erupted in 2004.

Indonesia has about 500 volcanoes, nearly 130 of them active and 68 classified as dangerous.