Indonesia’s Mount Dukono volcano in North Maluku province erupted on Friday morning at 7:41 a.m. local time, killing three people, including two foreign nationals and one local resident. Authorities reported that at least 20 climbers remain trapped on the mountain, prompting an ongoing rescue operation. Five others were injured in the eruption, and the victims include two Singaporean citizens, according to local officials.

Police Chief Erlichson Pasaribu confirmed the fatalities, while local rescue agency head Iwan Ramdhani told Reuters that efforts are continuing to locate and evacuate the trapped climbers. Among those stranded are nine Singaporeans and several Indonesian nationals. The eruption sent volcanic ash up to 10 kilometers into the sky, leading authorities to issue the third-highest alert level for the volcano.

Rescue teams are working under challenging conditions as ash clouds and unstable terrain complicate access to the affected area, according to officials cited by BBC and Reuters.