Luton town centre drew to a standstill as firefighters tackled a blaze above several shops on St George's Square.
The blaze broke out above foot businesses on the corner of Manchester Street and Gordon Street.
Smoke continues to billow out of the roof as Beds Fire and Rescue Service works to bring it under control using their aerial platform.
Scores of bystanders watched to see the fire service in action.
Bedfordshire Fire and Rescue Service has been approached for comment.