The Russian Navy’s Akula II-class nuclear-powered attack submarine Nerpa has successfully completed its first phase of new sea trials in the Sea of Japan.

The submarine, which is intended for the Indian Navy, suffered setbacks during trials after a fatal gas leak cost the lives of 20 crew members and caused $60m-worth of damage to the vessel

The submarine has since completed the first set of sea trials on schedule and is now preparing for the second phase of trials.

Equipment for performance checking and adjustment work will be installed on board the submarine during the second set of trials.

The Indian Government has paid $650m for a ten-year lease of the 12,000t K-152 Nerpa, an Akula II-class nuclear-powered attack submarine.