Criminals looted Rs 50 lakh from the Maripur branch of Axis Bank in the district, around 70km north of Patna, on Wednesday afternoon.

Twelve men entered the building around 1.50pm and barged into the bank, located on the third floor, armed with pistols. They had covered their faces with masks and helmets and upon entering the bank, roughed up the guard and snatched his gun away.

After this, one of them forced bank manager Santosh Kumar Bharti to hand over the keys to the locker at gunpoint. The others held the customers and bank employees at gunpoint, threatening to shoot if anyone resisted.

The robbers looted Rs 50 lakh in 15 minutes and fled without any further commotion. Bank officials alerted the police immediately after the men left.

No one was injured.

According to eye witnesses, the robbers, all in their thirties, had arrived to the bank on four motorbikes. Two of them stayed near their parked vehicles and the other 10 went for the loot.

Bank guard Ajay Kumar Singh told The Telegraph that the robbers had roughed him up and abused him.

"They took away my gun," he said. "They took the money and escaped via Gobarshahi Road."

Inspector-general of police (Tirhut zone) Parasnath, senior superintendent of police Vivek Kumar, superintendent of police (city) Anand Kumar and deputy superintendent of police Ashish Anand rushed to the bank to question the employees and the customers who were present at the time of the loot.

Bank manager Santosh Kumar Bharti said Rs 50 lakh had been robbed from the currency chest.

"We are looking at the CCTV footage to ascertain the criminals' identities," said Ashish.

Talking about the modus operandi, he said it appeared to be handiwork of a gang.

"We are conducting raids to arrest suspected bank robbers who are active along Muzaffarpur, Sitamarhi, Vaishali, Saran, East Champaran, Darbhanga and Samastipur," the officer said.

Parasnath said: "Three separate teams have been constituted to investigate the case and arrest the criminals."