A gang of armed criminals looted a little over Rs 22 lakh from a bank's cash van in Jehanabad, around 50km south of Patna on Saturday.

Police said the incident took place around 2.30pm when a private security agency's vehicle hired by the bank was carrying money in an iron box to upload cash in automated teller machines (ATMS) in the district.

Jehanabad superintendent of police (SP) Aditya Kumar said six criminals riding on three motorbikes intercepted the cash van near Raja Bazaar Naya Tola in the district headquarters town. They took the private security guard, Birendra Sharma, hostage and snatched his gun.

The robbers escaped with the money on their motorbikes. Though the police chased the robbers, they managed to escape. The gun belonging to the security guard was later recovered from an abandoned place, the SP told The Telegraph over phone.

Police officials posted at the Jehanabad town police station under whose jurisdiction the site of occurrence falls, revealed that the money was withdrawn from Punjab National Bank and was to be uploaded in different ATMs.

An investigating officer said the criminals had done a recee before the incident. "Some motorbike-borne youths were seen moving around the PNB ahead of the departure of the cash van," he said, adding that raids were carried out to nab the culprits.

The SP earlier said the guard, who was escorting the vehicle, had been detained for interrogation. "It is quite surprising that the money was being escorted by a single security guard," he said, adding that the criminals involved will be brought to book at the earliest.

The police also quizzed cash custodians of the bank - Sanjiv Kumar, Ravi Ranjan and Rajesh Kumar Saxena. The driver of the vehicle, Ramesh Kumar, told interrogators that all the robbers were in the age group of 22 to 30 years.

On June 5 this year, criminals had looted Rs 3 lakh from a cash van of an insurance company. The money was to be deposited in the Axis Bank in Jehanabad town, a police officer posted at the Town police station said.

"There is striking similarity in the two incidents of cash loot in quick succession. It seems that a particular gang is involved in the both the incidents. Their modus operandi is the same," the police officer said.