India, Feb. 27 -- The authorities heightened security in Manipur's Imphal West district on the final day of the seven-day ultimatum for voluntarily surrendering looted and illegally held arms and ammunition as part of efforts to end the protracted ethnic violence in the northeastern state.

Imphal West district police superintendent issued an order on Wednesday citing the "prevailing security situation" and instructed top officers of his force, commando teams, the Central Armed Police Forces, Assam Rifles, and the Army to secure 10 key locations.

On Tuesday, radical Meitei group Arambai Tenggol said it would give up illegal weapons only when its terms and conditions are accepted. Governor Ajay Kumar Bhalla on February 20 asked all commun...