India on Thursday (Aug 29) formally commissioned its second Arihant-class submarine into its navy. The nuclear-powered submarine, INS Arighat, is considered an advanced version of its predecessor.

The 6,000-ton vessel was built at the Ship Building Centre in the port city of Visakhapatnam and it was revealed for the first time in 2009. India's first nuclear armed submarine INS Arihant is ...