According to reports in Brazil, the men entered the emergency reception area of the Hospital Norte D'Or claiming to need medical attention.

"This is why they were not stopped by the doorman," Police Deputy Jorge Zahra said.

"Two of them were armed and two or three collected the valuables, such as cell phones from the people they found accompanying those in need of medical care."

One witness, who was visiting the hospital to pick up test results, said: "I don't know how to say it, not even the sick are safe."

The men entered the building claiming to be sick

The rest of the hospital security on duty were forced to hand over their weapons by the gunmen.

Deputy Zahra said a number of the witnesses were able to potentially identify some of the gunmen.

"Looks like there are two victims, one of which managed to identify, by looking through some of our photos, one of the suspects," he added.

"We have two teams on the street trying to put the miscreant in jail."

No one was injured or has been detained in connection with the crime.