The 12552/12551 Kamakhya–SMVT Bengaluru AC Superfast Express is a Superfast Express train belonging to Indian Railways – Northeast Frontier Railway zone which connects cities Bangalore the capital of Karnataka and Guwahati the capital of Assam, that runs between Kamakhya Junction and Sir M. Visvesvaraya Terminal, Bengaluru in India. It is the longest running AC Superfast Express and 23rd overall longest running train service of Indian Railways.