A tribal group in Manipur today reimposed an indefinite blockade on a national highway, demanding adequate supplies of essential commodities to Kuki-Zo communities in hill areas of the state. NH 2, which connects Imphal with Dimapur in Nagaland, is seen as the lifeline of land-locked Manipur. The Committee on Tribal Unity (CoTU) had issued an ultimatum that a blockade will begin in three days if things don't improve by then.