Five people were killed near Diyungbra in Assam's Dima Hasao district late Thursday night after their trucks were attacked, allegedly by members of the Dimasa National Liberation Army (DNLA).
Assam Police said the terrorists fired several rounds at the truck drivers and other people before setting seven of the trucks on fire. Security personnel rushed to the spot - Rangerbeel on Umrangsu Lanka Road - and recovered the bodies.
"Information we got from the ground was that five suspected militants, who first fired from automatic weapons, set the trucks ablaze. We suspect the militant organisation DNLA to be behind this attack," Jayant Singh, Superintendent of Police (Dima Hasao District), said.
The Police and the Army's Assam Rifles unit are conducting a massive combing operation in the region and an investigation has been launched, Mr Singh said.
The incident took place a little over 200 km from Guwahati. The trucks were carrying coal and other material for a nearby cement manufacturing plant.
The attack came two days before Northeast Frontier Railway (NFR) runs a special tourist train that will be equipped with Vistadome coaches that have an all-glass roof and provide a 360-degree view.
The first of these trains in northeast India is expected to depart from Guwahati on Saturday, and is scheduled to travel to New Haflong via Dima Hasao district.
In light of the suspected DNLA attack though, questions have been raised over the safety of the train.
About a decade ago, when attacks were frequent, the Railways ran bullet-proof engines in Dima Hasao. That was when the DHD(J) faction, or the Black Widows, was active.
In 2008 the DHD(J) carried a similar attack - truck were set on fire and 10 people died.
The Dima Hasao district - one of Assam's three hill districts - was earlier a hotbed of insurgent activities and groups. However, over the past five years a degree of calm had prevailed.
In May, security forces killed six DNLA terrorists in an encounter in the Dhansiri area of Karbi Anglong district. Arms and ammunitions were recovered from their possession, the police said.
This operation was after the DNLA killed a young man in the Dhansiri area.
Formed in 2019, the DNLA is believed to be active in the Dima Hasao and Karbi Anglong disticts, as well as parts of neighbouring Nagaland.