Indonesia's navy is searching for a submarine that went missing north of the resort island of Bali with 53 people on board, the military said on Wednesday.
The KRI Nanggala 402 submarine was participating in a training exercise when it missed a scheduled reporting call.
The submarine is believed to have disappeared in waters about 60 miles north of Bali, officials said.
The navy has deployed scores of ships to search the area, including a hydrographic survey ship, and has asked for help from Singapore and Australia.
The Defense Ministry said the submarine lost contact after being granted clearance to dive. It said a helicopter later spotted an oil slick near the dive's starting position.