Imphal, April 24 :    Imphal, April 24:  A Naga militant outfit may have been behind the killing of Research and Analysis Wing (RAW) functionary Pankaj Kumar Mishra here yesterday, according to Manipur director-general of police D.S. Grewal. The police chief told The Telegraph here today that the two assailants who gunned down Mishra at Dewlahland in Imphal appeared to be 'tribal youth'. He said a team of police officials would go to Ukhrul district to investigate the killing. A deputy field officer in the RAW-affiliated Special Bureau, Mishra was recently transferred to the state capital after a two-year stint in Ukhrul district. Two unidentified gunmen called him out of his house yesterday and shot him dead. While Grewal said the assailants were probably Naga militants, an intelligence source said they could be members of a major valley-based insurgent outfit. He expressed surprise over the attack on Mishra, saying the Special Bureau was not involved in any counter-insurgency move. RAW or Special Bureau officials were unavailable for comments. A police official said it was difficult to contact RAW operatives. 'They do not even give their telephone numbers to us,' he said. The official said RAW operatives had been deployed in Manipur to keep tabs on 'agencies' across the border with Myanmar. He said the intelligence agency probably had clues to Mishra's killing, but were loath to share the information with the police. 'The only thing RAW officials have enquired about is the progress of our investigation,' the police official said. Unofficial sources said Mishra was a bachelor and allegedly had a relationship with a Naga girl while being posted at Hundung in Ukhrul district. The Special Bureau official may have been killed by Naga militants who did not approve of the relationship, they said. However, the police ruled this out. They said a love affair was not a plausible reason for the killing. Postmortem on Mishra's body was conducted at the Regional Institute of Medical Sciences here today. Four jawans injured Four jawans of the Army's 59 Mountain Brigade were injured in a bomb attack by suspected valley-based militants at Khonghampat in Imphal West district today. The rebels triggered the blast when an Army convoy returning to Leimakhong from Imphal was passing by. The incident took place at 4.15 pm. The injured jawans are undergoing treatment at the Leimakhong Military Hospital. Incensed by the attack, a group of Army personnel allegedly beat up civilians in the area. Three of the victims were admitted to the J.N. Hospital in Imphal.