On December 17, India failed an attempted launch of a K-4 submarine-launched ballistic missile from a submerged pontoon. Indian officials have not released a cause of failure, but according to one Indian news source, the it was caused by “a failure in the missile’s ignition following its ejection from the submerged pontoon.” The K-4 is currently in development by the Defense Research and Development Organization (DRDO), and is intended for deployment on the Indian Navy’s Arihant-class ballistic missile submarines. It is expected to possess a range of 3,500 km. This launch was the fourth test of the K-4, and India plans to conduct another missile test from on-board the INS Arihant (S-73).