Assam Rifles sources said on Tuesday there was no exchange of fire during Saturday's raid at the camp, located inside the jungle.
The rebels managed to escape as they appeared to have got wind of the raid.
CNF has launched an armed struggle against the Myanmarese military rulers for federal autonomy for Chin Hills and restoration of democracy.
The raid was conducted following a tip-off about the hideout, strategically hidden behind two steep hills to carry on activities against Myanmarese authorities, the sources said.
Over 200 activists were being trained in the hideout, according to reports.
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