Indian security forces have launched a large operation against separatist rebels in a national park in the north-eastern state of Assam.
Indian forces have been fighting Assam rebels for two decades
Nearly 2,000 soldiers and armed policemen have moved into the park that borders the neighbouring state of Arunachal Pradesh.
An Indian army spokesman says it is targeting rebels of the United Liberation Front of Assam (Ulfa).
Ulfa has been fighting for a separate Assamese homeland for two decades.
The soldiers began moving into the Dibru-Saikhowa national park around midnight.
The spokesman, Lt-Col Narendra Singh, said security forces had established operational bases inside the forest and the rebels would be attacked soon.
But he said the troops and policemen were yet to trace the guerrillas, although a deserted rebel base had been found with some weapons, ammunition and explosives.
Col Singh said the massive operation had been launched on the basis of intelligence reports that an Ulfa mobile battalion had set up a base inside the park.
From there the rebels would carry out hit-and-run raids and bombings in Assam's northern districts where much of the state's tea estates, oil and gas fields are located.
"This Ulfa battalion is the most dangerous, they specialise in sabotage," said a recently retired army officer, Lt-Gen Gaganjit Singh.
Chances of Ulfa opening a peace dialogue with Delhi faded after the rebel leaders made it clear they would only talk if India agreed to discuss Assam's sovereignty.
The Indian government has rejected the demand, saying the rebels must talk without conditions as other separatist groups in the country have done.