Indonesia’s navy is searching for a submarine with 53 people on board which has gone missing in waters north of the island of Bali.

The vessel was conducting a torpedo drill on Wednesday but failed to relay the results as expected, a navy spokesman said.

A search is under way for the German-made submarine, KRI Nanggala-402, and its crew.

Indonesia has asked authorities in Australia and Singapore for help with the hunt, the country’s military chief Hadi Tjahjanto told Reuters.

“We are still searching in the waters of Bali, 60 miles (96km) from Bali, (for) 53 people,” he told the news agency in a text message.

He said contact with the submarine was lost at around 4.30am local time.

The 1,395-tonne vessel was built in 1978, according to the Indonesian cabinet secretariat’s website.

It underwent a two-year refit in South Korea which was completed in 2012.