 The first elevated line of the Delhi Metro was inaugurated by Atal Bihari Vajpayee , the Prime Minister of India , on 24 December 2002 & the first underground line was inaugurated by Dr Manmohan Singh on 20 December 2004 , and thus , it became the second underground rapid transit system in India , after the Kolkata Metro . The first underground section of Delhi Metro was Vishwa Vidyalaya - Kashmere Gate section which included 4 @.@ 5 km tunnel & 4 stations namely Vishwa Vidyalaya , Vidhan Sabha , Civil Lines & Kashmere Gate station . This project was constructed by Kumagai @-@ Skanska @-@ HCC @-@ Itochu JV or <unk> @-@ JV , a joint venture between Kumagai Gumi , Skanska , Hindustan Construction Company & Itochu . 
