An Indian navy official said 18 sailors are trapped aboard a submarine that caught fire and sank after an explosion. He says other sailors are working frantically to save them.

The diesel-powered submarine sank early Wednesday at its home port in Mumbai. The fire is out but the official says the sailors have not been recovered and it is unclear whether any were killed or injured. The officer spoke on condition of anonymity because he was not authorized to talk to reporters.

The officer said that when the blast occurred, some sailors of other nearby units jumped into the sea in panic. He says some were injured and hospitalized.

Navy spokesman Narendra Vispute said efforts are being made to determine the safety of the personnel and salvage the submarine. (AP)