Indian wildlife workers kidnapped
The three men and three women, all Indian nationals, were abducted at the Manas Tiger Reserve in Assam state, said Anupam Sharma, a WWF-India official.
More than 30 groups in the north-east have been fighting for decades for independence from India or wide autonomy in the region, about 1,000 miles east of New Delhi. The area near the tiger preserve is a stronghold of the National Democratic Front of Bodoland, a rebel group opposed to peace talks with the Indian government.
Mr Sharma said people living near the tiger reserve reported the attack to other WWF-India volunteers working in the area.
He said the volunteers had been taking a census of the reserve's tiger population. The park, which spans into neighbouring Bhutan, has a sizable population of Royal Bengal tig-ers and wild Asiatic elephants.