India has deployed up to 2000 extra troops to the northeastern state of Assam following a wave of deadly attacks against migrant workers.
Security forces are looking for members of the outlawed separatist rebel group, the United Liberation Front of Asom, who they say are behind the attacks.
Military officials say troops are scouring wide stretches of forest and mountainous terrain along Assam state's northern border with Arunachal Pradesh state.
At least 70 people, mostly Hindi-speaking laborers from Bihar state, have been killed over the last four days. Thousands of migrant workers have fled.
ULFA rebels blame non-local migrants for for taking scarce jobs and the federal government for neglecting development in the region.
Rebels have been fighting for an independent Assamese homeland since 1979 and have targeted migrant workers before.
Some information for this report was provided by AFP, AP and Reuters.