Prime Minister Narendra Modi on Wednesday unveiled multiple metro projects across the country, including India's first underwater metro line in Kolkata, reported news agency PTI.

The Rs 4,965-crore Howrah Maidan-Esplanade section of Kolkata Metro's East-West Corridor, which has the first transportation tunnel "under any mighty river in India", was inaugurated by the PM. The stretch also has the deepest metro station in the country -- the Howrah metro station, reported PTI.