Jakarta: Neighbouring countries offered help even as search for an Indonesian submarine that went missing with 53 crew on board continued on Thursday.
The defence ministry said Australia, Singapore and India had responded to requests for assistance. Indonesian military chief Hadi Tjahjanto said the contact with the vessel was lost at 4:30 a.m. and a search was underway 60 miles (96 km) off Bali.
The oil slick could indicate damage to the vessel or could be a signal from the crew, the navy said.
The 1,395-tonne KRI Nanggala-402 was built in Germany in 1977, according to the defence ministry, and joined the Indonesian fleet in 1981. It underwent a two-year refit in South Korea that was completed in 2012.
Indonesia in the past operated a fleet of 12 submarines bought from the Soviet Union to patrol the waters of its sprawling archipelago.
But now it has a fleet of only five including two German-built Type 209 submarines and three newer South Korean vessels.