Ranchi police on Friday busted a gang of thugs, involved in at least four crimes including the Rs 10-lakh gunpoint snatching last week, by arresting three members including the mastermind.

Hunt is on for a fourth accomplice of Narendra Singh (35), Benjamin Tirkey (45) and Rajesh Kumar Shrivastava (35), all residents of Ranchi district.

SSP Kuldeep Dwivedi said the trio were arrested with a 9mm pistol, which was apparently used in the loots, three rounds of ammunition and Rs 3.36 lakh, probably a part of the booty bagged from the bank official who was targeted near Ratu block office on July 18.

"Narendra, also known as Chouhan in the gang, masterminded the crime. But, probe by our technical cell first led us to Benjamin Tirkey, a resident of Lada village in Nagri police station area. We arrested him around 10am from Ring Road in Ratu police station area when he was heading towards Ranchi from Panki," the SSP said.

Based on Benjamin's interrogation, Rajesh and Narendra were arrested from Makmandro, also under Ratu thana, around 11am.

The district police chief revealed that the Chouhan gang had also pulled off the January 4 crime at Kamde in Ratu, where owner of Binko Petrol Pump Basant Kujur was robbed off Rs 99,760.

"The gang had targeted one Rajesh Kumar on July 8 near OTC grounds in Sukhdeonagar police station area and bagged Rs 40,000 while they had cleaned out Rs 6.66 lakh from Sambhavi Petrol Pump in Mecon Colony on February 22," SSP Dwivedi said.

Asked about the gang's modus operandi, the officer refused to divulge details at the moment, saying they were still looking for one more member of the gang.

Another officer said police were examining the role of a driver who usually drove the car in which bank official Brahmanand Pandey was targeted, but was on leave at the time of the incident last week. "We suspect the driver may have tipped the gang, but everything is subject to arrest and investigation," he said.

Pandey, an employee of Allahabad Bank's Umedanda branch, was carrying the cash from the bank's chest on Circular Road in Lalpur in the capital to his office in Burmu, 40km away, around 11am on July 18 when he was targeted.

Bikers overtook his office car and signalled the driver to stop near the block office. As soon as the driver did so, they held a gun to Pandey's face and asked him to part with the bag of money. They took the cash and sped away.