In major relief for the Indian Navy, the government has approved a medium refit and life extension programme for six of its conventional attack submarines. The refit will involve extensive upgradation of systems and sensors, including the fitment of new generation sonars on at least two of the submarines. The programme envisages upgrade of four Russian Kilo-class submarines and two Type 209 Shishumar-class submarines. The navy's submarine arm has been in a state of distress for years now, compounded by the tragedy that struck the INS Sindhurakshak at the Mumbai Naval dockyard in August last year. The navy now operates 13 submarines on paper, but only eight of them are reportedly in operational condition. The INS Sindhuratna, which experienced a fire that killed two officers aboard it earlier this year, has been out action since the accident, but is reportedly fit to get back to sea soon. The Defence Acquisition Council has additionally approved anti-submarine warfare and detection systems, including active towed array sonars and torpedo decoy systems for the future P15B destroyers and P17A stealth frigates.