The Indonesian Navy is looking for a submarine in its fleet with 53 people on board with which it lost contact on Wednesday morning after exercises off Bali

But where did the KRI Nanggala 402 go?

The Indonesian navy is looking for a submarine in its fleet with 53 people on board with which it lost contact on Wednesday morning after exercises off Bali, military authorities said.

Jakarta has sent warships to the area and asked for help from Singapore and Australia, Indonesian armed forces commander Hadi Tjahjanto told AFP.

The submarine "is at a depth of 700 meters"

The submarine "sits at a depth of 700 meters" north of the island of Bali "with 53 crew members on board," he said.

The submarine, the KRI Nanggala 402, did not resume contact with its base after 3:00 a.m. local time (19:00 GMT Tuesday), said First Admiral Julius Widjojono, spokesman for the navy.

The navy is "currently conducting research."

"We know the area but it is quite deep," he added.

The German-made submarine was to participate in maneuvers, including torpedo fire.

The Indonesian Navy has a fleet of five submarines in total, German and South Korean built.

The KRI Nanggala 402 was built in 1978, according to a government website and was subsequently modernized.