A man is critically ill in hospital after he was attacked in Leicester's Market Place.
The 29-year-old suffered a "significant" head injury as a result of the assault, which happened at 12.20pm yesterday.
He underwent emergency surgery and is said to be in a critical condition.
Police are searching for two men in connection with the attack, which happened near the Santander and Yorkshire banks.
Around two hours later the man collapsed in a shop in Belgrave Gate and was taken to hospital in Coventry.
The men who police believe carried out the assault are black, while the injured man is white.
Officers have appealed for witnesses. They said the injured ,an was wearing an orange sweatshirt.
Detective Sergeant Simon Head, of the force's serious crime team, said: "We are keen to speak to anyone who saw the victim between the initial assault and him collapsing.
"Did you see him in the city centre? Did he speak to you?
"At this time of day there would have been a lot of people in the Market Place area who may have seen the initial incident, or who may have seen the man in the orange top.
"I would ask them to contact me - no matter how small the information it may prove vital to finding out what happened to this man."
Contact Det Sgt Head on 101 or Crimestoppers, which is anonymous, on 0800 555 111.
