At least six hikers have been killed and others severely injured by a wildfire on a mountain in Indonesia.

The incident took place on Sunday at Mount Lawu on the main island of Java.

Officials believe the fire was caused by a bonfire started by hikers that was not extinguished properly, and spread quickly due to dry conditions.

Wildfires frequently take place during Indonesia's dry season, which has also exacerbated illegal forest fires in Kalimantan and Sumatra.

Officials said at least three people had sustained severe burns, and all the dead and injured have been brought down from the mountain.

'Previous cases'

Local disaster agency official Agung Lewis told AFP news agency that the area the hikers were in had been closed off earlier.

"The area is actually closed for hiking because there had been previous cases of wildfires due to the dry weather, so we suspect these hikers could have used unofficial routes," he told the news agency.

Officials are still checking to see if there are any other hikers stuck on the mountain.

(BBC)