An all-clear was issued in the course of the afternoon after several dozen police officers and police specialists had searched the 2500-seater conference hall and adjacent rooms. The FIFA Congress was therefore able to continue as planned with no significant problems. The police are currently investigating the source of the threat. Zurich City Police detectives have begun looking into the case. In addition to officers of the Zurich City Police, the operation included the rescue services, Zurich Forensics Institute (FOR) and dog-handlers belonging to the Zurich Cantonal Police. Siewerdtstrasse was blocked off for several hours.