The ultras picked up the youths, identified as Laxman Koda (22), Makhru Koda (24) from Jamunia village last night and shot them dead in a nearby forest, Superintendent of Police Ashok Kumar said.
The ultras killed the two for being police informers, he said.
The bullet-riddled bodies of the youths have been recovered and sent to Sadar hospital in neighbouring Munger district for postmortem, the SP said.
Raids were being carried to nab those responsible for the murder, Kumar added.