Police hunting an offender who left a suspicious package at a Refugee Council office in Birmingham issued CCTV images of a man they wish to trace.
Detectives believe the incident, which brought large parts of the city centre to a standstill on July 13, may have been racially motivated.
The security alert forced the evacuation of the Refugee Council's premises in Lionel Street and other nearby office buildings, as well as disrupting train and tram services and forcing police to close local roads and a nearby canal.
Army bomb disposal experts were called in to deal with the suspicious package, which was found to pose no risk to the public.
Detective Sergeant Mick Ross, who is investigating the incident, said: "This was a cowardly crime which left innocent members of the public fearing for their safety and the safety of their family and friends.
"We are keen to speak to the man captured in the CCTV images as we believe he may hold vital clues in finding those responsible for the scare."
Anyone with information should call West Midlands Police on 0345 113 5000 or the Crimestoppers service, anonymously, on 0800 555 111.
