Armed robbers threatened guards when they held up a security van outside a supermarket.
Two men, brandishing what police described as "bladed weapons" targeted G4S guards who were delivering money to the cashpoint outside the Tesco Express store in London Road, next to Leicester railway station.
They grabbed cash boxes before escaping in a vehicle at about 6.30am yesterday.
Police cordoned off the area around the cashpoint while forensic investigators examined the scene.
Businesses in the area had already started to prepare for the day's trading at the time of the raid.
A member of staff at Greggs sandwich shop next door, who asked not to be named, said: "It's scary to think it happened just outside at that time of the morning when people are about. "When we tried to open the front, there was police tape spread out along the street and we were told we couldn't open at first."
Another shopkeeper in London Road said: "I heard they had been watching the security guards and they knew their times. You hear about things like this happening a lot lately."
G4S would not say how much cash was taken during the robbery.
A spokesman said the two security guards were not hurt during the raid, but have been offered counselling.
He said: "The psychological impact that attacks of this nature can have on individuals should not be under-estimated.
"Our staff have the right to expect to be able to go about their duties without fear of attack and we are working with the police so that those responsible for this incident can be made accountable for their actions in court."
Descriptions of the armed men and the getaway vehicle have not been released by police.
A police spokeswoman said: "We are looking at things like CCTV to give us more clues about what happened.
"We know that at 6.26am two men in a vehicle threatened security guards before making off with cash boxes. No one was injured."
Anyone with information can call police on 101 or alternatively contact Crimestoppers on 0800 555 111.
