image sourceTwitterimage captionPeople in nearby buildings captured grainy video of the shocking incident on smartphones

Bank robbers in Brazil who used hostages as human shields by forcing them to lie on the roofs and bonnets of their getaway cars told them they would be shot in the face if they did not cling on, one of the hostages has said.

They took at least 11 people hostage and held them for nearly two hours.

Police are searching for the bank robbers, most of whom are on the run.

Three people, one of them a suspect, were killed in the robbery in the city of Araçatuba in São Paulo state.

Threatened at gunpoint

"All I could think about is that I would die," one of the hostages told Brazilian new site UOL [in Portuguese].

The man, who asked to remain anonymous for security reasons, said a gunman carrying a rifle stopped him as he rode through the streets on his motorbike.

image sourceAFPimage captionThe gang set a number of cars alight

Even though shots had already been ringing out through the city, the man was not aware of the danger.

"I'd heard a commotion, but I thought it was fireworks. Suddenly, a man pushed me off my motorbike and told me to stop. At first, I thought it was a police checkpoint but then I saw they were assailants," the man told UOL.

He described the robbers as "aggressive" and determined to intimidate their captives.

"If they saw someone peeking from a window, they'd shoot in that direction to frighten everyone and show us they weren't playing," he said.

Another hostage told Brazilian news site G1 [in Portuguese] how he was stopped and used as a human shield.

"They told me to get out of the car, tore off my shirt and threw my cap on the ground," he said.

"I was put onto the bonnet of a car and told: 'If you let go, if you try to throw yourself off, I'll stop the car and shoot you in the face.' I think I have never held on so tightly to anything as I did then."

The hostage described how he managed to hold on as the car was driving over speed bumps and potholes.

The mother of another hostage said it was a miracle her son had survived.

"He was forced to get onto the bonnet of one of the cars and told to just hold on with his hands. He almost fell and died," the mother told UOL.

She also said that the hostages had been released in a rural area and it had taken them hours to walk back.

How the robbery unfolded

A group of about 20 robbers targeted three banks in Araçatuba, a city of some 200,000 people, 575km north-west of São Paulo.

They managed to break into two banks and damaged a third one in the early hours of Monday local time.

It is not yet clear how much money they made off with, but officials said that they had gained access through the underground vault in one of the banks.

The robbers were heavily armed and their robbery appears to have been carefully planned.

They not only cut off key access roads to the city with burning vehicles, but also attacked the local military police station and placed some 40 explosive devices at 20 different locations around the city. Police say the devices are triggered by remote sensors.

One of them exploded as a man cycled past. He was seriously injured and both his feet had to be amputated.

They also used drones to monitor police activity during and after the robbery.

Police said they had arrested two suspects so far and found seven of the vehicles abandoned in a rural area outside Araçatuba.