Mount Semeru volcano spews hot ash and smoke into sky on Indonesia’s Java island

Natural disasters agency warns residents to be vigilant for signs of danger

Mount Semeru’s alert status was raised to the country’s third-highest level last year (AP)

The highest volcano on Indonesia’s most densely populated island has spewed hot ash and smoke as high as an estimated 5.6km into the sky, triggering a warning from the country’s natural disasters agency.

The National Disaster Mitigation Agency warned people who live in the villages on the slopes of Mount Semeru on the island of Java to be vigilant in looking for signs of danger on Saturday, but stopped short of ordering immediate evacuations.

Raditya Jati, an agency spokesperson, said that people around the river basin on the slopes of the 3,676-metre-high mountain should beware of high rainfall intensity that can trigger lava floods.

Despite the concerns, Indonesia’s Volcanology and Geological Hazard Mitigation Centre did not raise Mount Semeru’s alert status on Saturday, which is already at the third-highest level since it began erupting in May.

The volcano spewed hot ash for 3,000 metres in early December, triggering panic among villagers.

More than 500 people living by Mount Merapi, the country’s most active volcano, were also told to evacuate after it began to spew avalanches of hot clouds on Thursday morning last week.

Indonesia, an archipelago of more than 250 million people, is prone to earthquakes and volcanic eruptions due to its place on the Pacific “Ring of Fire” and government seismologists monitor more than 120 active volcanoes.

Early on Friday, a strong 6.2-magnitude earthquake shook the country’s Sulawesi island, killing at least 46 people and damaging hundreds of homes in the local area.

Saidar Rahmanjaya, the head of the local search and rescue agency, said on Saturday that operations were focused on about eight locations in the city of Mamuju, where people were still believed to be trapped.

Cargo planes carrying food, tents, blankets and other supplies from the capital of Jakarta have been sent for distribution in temporary shelters in the area.

However, damaged roads and bridges, power blackouts and a lack of heavy equipment has hampered rescue efforts so far this weekend.

Additional reporting by agencies