India's Defence Research and Development Organization (DRDO) have successfully flight-tested an underwater-launched missile called K-4. The about 3,000 km range missile was reportedly launched from a submerged pontoon submerged more than 30 metres deep in the sea off the Visakhapatnam coast. As of now, nearly 10 development trials of K-15 missile have already been completed. It is expected to undergo several more tests from submerged pontoons and finally from submarines before being getting operational. Developed by DRDO, K-4 is an indigenous intermediate-range nuclear-capable submarine-launched ballistic missile (SLBM) which is most likely to arm the Arihant class submarine.