JAKARTA (REUTERS, AFP) - Indonesia's Mount Sinabung volcano sent a cloud of hot ash as high as 3km (1.86 miles) on Tuesday (March 2), in its first big eruption since August last year, the country's volcanology centre said.

Mount Sinabung's activity has increased since August last year and the alert for the volcano in North Sumatra province has been placed at second highest level.

No casualties were reported as official had earlier urged people to stay at least 3km from the crater, Indonesia's Volcanology and Geological Hazard Mitigation Centre said.

No evacuation orders have been issued, and there has been no reported flight disruption.

"There is no indication of increasing potential danger," the agency said in a statement.

Videos on social media showed little panic among residents over the eruption, which sent a column of white ash into the blue sky.

Mr Wirda Br Sitepu, a 20-year-old resident, told Reuters that the situation had calmed and said "the mountain is not erupting, and the ash has decreased."

Sinabung, a 2,460-metre volcano, was dormant for centuries before roaring back to life in 2010 when an eruption killed two people.

After another period of inactivity, it erupted again in 2013 and has remained highly active since.

In 2014, an eruption killed at least 16 people, while seven died in a 2016 blast.

Indonesia - an archipelago of more than 17,000 islands and islets - has nearly 130 active volcanoes.

It sits on the "Ring of Fire", a belt of tectonic plate boundaries circling the Pacific Ocean where frequent seismic activity occurs.

Mount Merapi on Java island, one of the world's most active volcanoes, also erupted this week, emitting lava on Monday.