Around 30 Maoists raided Urain village last night and shot dead guard Arjun Mandal after dragging him out of a Durga puja pandal, Superintendent of Police Ashok Kumar said.
The body has been sent for post-mortem at the Sadar Hospital in neighbouring Munger district, he said.
Mandal was deputed on duty for Durga puja in Urain village, Kumar said.
A case has been registered in this connection and raids were being carried out to nab the culprits, the SP said.