Two Indian sailors were found dead Thursday a day after the submarine they were on filled with toxic smoke , authorities said . The accident , the latest in a series of problems plaguing the Indian fleet , prompted the chief of the country 's navy to resign . Seven crew members of the Russian-built submarine , the INS Sindhuratna , have been hospitalized after inhaling smoke emanating from one of the vessel 's compartments early Wednesday while it was off the coast of Mumbai , the navy said . Two other sailors on the submarine had been reported missing . Their bodies were found Thursday in a smoke-affected compartment of the vessel , authorities said . Adm. D.K . Joshi , the navy 's chief of staff , stepped down Wednesday after news of the problems on the submarine emerged , the government said . Joshi took `` moral responsibility for the accidents and incidents which have taken place during the past few months , '' the defense ministry said in a statement . The Indian navy declined to provide an exact number of how many incidents had taken place on vessels in recent months , saying only that there had been `` a couple of serious accidents involving submarines . '' In August , an explosion and fire sank another of India 's Russian-made submarines , the INS Sindhurakshak , killing all 18 sailors on board . That was the navy 's deadliest peacetime disaster . The cause of the smoke Wednesday on the Sindhuratna is still under investigation , the navy said . The Indian navy has been struggling to modernize its aging submarine fleet , which , like much of the Indian military , relies heavily on Russian hardware . Analysts say the current number of submarines is far fewer than India needs to patrol is lengthy coastline , but plans to update the fleet have been held up because of technical problems , bureaucracy and higher-than-expected costs .
18 sailors who were missing are found dead , authorities say . Seven other sailors are hospitalized after toxic smoke on a submarine . The chief of the the INS Sindhurakshak has stepped down following a series of problems on vessels . In a day , an explosion on another Russian submarine killed all Seven sailors on board .