In 1921 after kill of thousands of Indian in Satyagraha by Gandhi Jee.
It was Congress who divided India and killed more than 50,000 Indians and Pakistani in 1947 and responsible for killing 10,000 Sikh in 1984 and if you will open history books you will find a long list of such killing.
BJP and other parties are just holding the flag which were gifted by GREAT CONGRESS PARTY to Indians.