Police have so far failed to identify the group or the motive behind the killing of five persons in Upper Assam’s Tinsukia district on Thursday.

Ulfa (Independent) has denied involvement in the attack that occurred at Bishoni Mukh Khergaon, around 2km from Dr Bhupen Hazarika Setu under Saikhow police station.

Additional director-general of police R.P. Meena said, “We have pressed all resources and are looking at all angles. We are close to finding the group behind the attack. I cannot say more than that.”

A police source said, “We have been able to identify the route used by the attackers. The track runs into Namsai district of Arunachal Pradesh, from where they seemed to have come and returned.”

Sadiya superintendent of police Prasanta Changmai said, “We have arrested Ulfa (I) linkman Dikla Gogoi in connection with the case. He was detained at a checkpost, around 2km from where the incident occurred. We produced him in court seeking police remand for seven days.”

“We have recovered 32 bullet casings from the site resembling those used in AK-series rifles. The number of bullets fired on the victims can be confirmed only after we receive the autopsy report,” he added.

Sources said AK-series rifles are usually used by Ulfa (I), who are known to conduct such operations. The militants cross the inter-state border through dense jungles and then take shelter in neighbouring Arunachal Pradesh.

Changmai said, “We had requisitioned for a permanent CRPF camp at Bishoni Mukh Kherbari and it has been accepted by the force.”

Locals have demanded security for the lone survivor as he is the only eyewitness to the attack.

The last rites of the deceased were conducted on Friday night.