Indonesian authorities are still trying to locate three missing hikers after rescuing 17 people trapped by the volcanic eruption of Mount Dukono on Halmahera island on Friday, a local rescue agency official told Reuters, Reuters reports.

Iwan Ramdani, the head of the local rescue agency, told Reuters that 17 had been found and evacuated. It is unclear how many Singaporeans were rescued.

Iwan said the search is still on for the three hikers who remain missing.

Survivors said three people, including two Singaporeans, died in the eruption, local police chief Erlichson Pasaribu told Reuters, but the rescue agency has yet to confirm the deaths.

The local rescue agency said earlier that 20 hikers were trapped by the eruption, including nine Singaporeans and 11 Indonesians.

Mount Dukono, located in North Maluku province, erupted on Friday at 07:41 a.m. local time (1041 GMT Thursday), spewing volcanic ash as high as 10 km (6.21 miles) into the sky, the country's volcanology agency said.

Authorities warned residents to refrain from any activities within 4 km (2.5 miles) of the crater.

The volcanology agency also warned of the risks of volcanic mudflow when it rains.

Indonesia sits on the Pacific "Ring of Fire," an area of high seismic activity atop various tectonic plates.