Officials divert flights from North Sumatra province and prepare for evacuation after eruption of mounts Sinabung and Merapi

This article is more than 6 years old

This article is more than 6 years old

Two volcanoes have erupted in Indonesia, prompting flight diversions and evacuation preparations.

Mount Sinabung in North Sumatra province has unleashed volcanic ash as high as 8,000 metres (26,250ft) in recent days, said the government volcano expert Surono.

The 2,600-metre Mount Sinabung has sporadically erupted since September after being dormant for three years.

Kety Shapazian (@KetyDC) Unbelievable @Reuters photo of Indonesia's Mount Sinabung spewing volcanic ashes on Monday. pic.twitter.com/nd4HgcEGq3

Officials raised the alert status of Sinabung to the second-highest level after an eruption early this month, prompting evacuation of more than 6,000 villagers living near its slopes. Its activities have continued since then, sometimes unleashing lava down the slopes.

"It was the strongest eruption in recent days," said Surono, who like many Indonesians uses a single name.

The transportation ministry spokesman Bambang Ervan said his office had issued a notice for all airlines to avoid routes near the mountain.

Residents in Medan, the provincial capital about 30 miles (50km) to the north-east, could see black smoke billowing from Sinabung.

Hours earlier, Mount Merapi, Indonesia's most volatile volcano in Central Java, spewed volcanic ash about 2,000 metres into the sky, causing ash to fall in several towns.

A woman carries a bucket full of ash-covered tomatoes in Mardingding, in the shadow of Mount Sinabung. Photograph: Roni Bintang/Reuters

The national disaster management spokesman Sutopo Purwo Nugroho said about 600 families had gathered for a possible evacuation.

Merapi, which is in Yogyakarta province, killed more than 300 people and caused the evacuation of 20,000 villagers when it burst back to life in late 2010.

Indonesia is located on the so-called Pacific Ring of Fire and has 129 active volcanoes, making it prone to seismic upheaval.