The rifleman during interrogation also confessed to having carried out two similar grenade attacks earlier this year at the behest of the KCP.

'On further questioning, Munal disclosed that he was involved in lobbing hand grenades at Shanti Hospital on July 27 and Langol View Clinic on July 28 here,' Kailun said.

Questions are now asked if there are more separatist elements in other security agencies.

'This is a very serious issue and we need to be vigilant against this new phenomenon of separatists infiltrating into the security forces,' another senior police official said.

There are 19 rebel groups active in Manipur, bordering Myanmar, with demands ranging from secession to autonomy and the right to self-determination. More than 10,000 people have lost their lives to insurgency in the state during the past two decades.