Indian police are searching for suspected rebels who ambushed a security patrol in the northeastern state of Manipur, killing 16.
A senior Indian officer says police are scouring the hills by helicopter and foot.
The Indian policemen were on post-election security patrol in the Bishenpur district following Friday's local elections in Manipur.
Authorities say they do not yet know which rebel group was behind the attack.
Manipur is a particularly impoverished region of India. Many who live there say the far-away central government ignores them, giving rise to a number of militants groups.
India has tried to crush the rebels with a tough anti-terrorism law that gives troops broad powers. Human rights groups say the soldiers use the law as an excuse to commit abuses.
Some information for this report was provided by AP and Reuters.