Sohsarai Police Station Officer In-charge J P Yadav said the deceased have been identified as Brajnandan Prasad (security guard) and Ranjit Kumar (cashier) of the cash van.
Prasad was the resident of Jadnandanpur village under Rahui Police Station and Kumar was the resident of Mansur Nagar village within the limits of Biharsharif police station of the district, Yadav said.
He said the armed miscreants shot dead the guard and the cashier when they were bringing in cash to replenish an ATM.
Yadav said the criminals fled from the scene after throwing away the rifle in a field.
The bodies have been sent to Biharsharif Sadar Hospital for post-mortem and raids were on to nab the miscreants, he said.