TIMELINE-The search for a missing submarine in Indonesian waters

A search for an Indonesian submarine that went missing with 53 crew onboard off Bali continued on Thursday after rescuers found an oil slick and neighbouring countries pledged to help.

The German-made, diesel-powered submarine, named the KRI Nanggala-402, is one of five submarines in Indonesia's fleet. The vessel can sustain a depth of 250-500 metres (820-1640 ft) but there are concerns it is currently lying at a depth of 600-700 metres, military officials said.

Following is a timeline of events provided by the Indonesian navy: WEDNESDAY APRIL 21

- 3:46 a.m. (1946 GMT): The Nanggala-402 dives - 4:00 a.m.: Submarine requests authorisation to perform a torpedo drill

- 4:25 a.m.: Before authorisation can be issued, contact with the KRI Nanggala-402 is lost - 8:00 a.m.: An oil slick is spotted in an aerial search around where the submarine had dived, though the navy says later it cannot determine whether the fuel is from the submarine

- 3:00 p.m.: Navy deploys ships to help in the search and issues a request for assistance which is answered by the Singaporean and the Australian navies THURSDAY, APRIL 22

- 12:08 p.m.: Navy says search vessels with sonar capability have not detected any sign of the submarine