Project startsSiliguri, Apr 5 (UNI) Construction of northeastern states''s longesttunnel - 6,610 mt - has started from Portal 1 of Tunnel no. – 7 ofthe Dimapur - Kohima New Rail line Project, located in Tsiepamavillage of Medziphema circle of Dimapur district in Nagaland,according to the Northeast Frontier Railway on Friday.