In separate statements today, the organisations said people should not take part in the celebrations and remain indoors to protest the 'forcible merger' of Manipur with the Indian union in 1949.
Security measures have been tightened particularly in the four valley districts of Imphal East, Imphal West, Bishenpur and Thoubal, official sources said.
Meanwhile, a powerful bomb was defused yesterday after it was found at Narainsena in Bishenpur district.