Mumbai, Aug. 13: A blast aboard the Indian Navy’s Kilo-class diesel electric submarine INS Sindhurakshak at the naval dockyard in Mumbai injured five sailors tonight.

Most sailors jumped overboard after the midnight blast, suspected to have occurred in the boiler, naval sources said. The five who were injured were rescued and taken to hospital ship INHS Ashwini, parked at the Mumbai dock.

The fire spread to another submarine of the same class, INS Sindhuratna.

“A total of 25 fire tenders brought the fire under control within an hour and a half of the blast. Senior officers have rushed to the spot,” the source said.

The blast, which appeared to have been caused by an electrical short circuit, could be heard in the city’s Kalaghoda area about 2km away.

The submarine had returned from Russia’s Zvezdochka shipyard earlier this year after being modernised and repaired.