Six banned militants groups operating in the north-east India have issued a joint statement calling for the 'boycott of Republic Day celebrations and a general strike on 26 January in the region. The outfits which have called for the strike included United Liberation Front of Assam, National Democratic Front of Boroland, Kamtapur Liberation Organisation, Manipur People's Liberation Front, National Liberation Front of Twipra and Tripura People's Democratic Front.