Police have now completed searches of the Monks Cross shopping centre in York and are satisfied there is no danger posed to the public.
The cordons have been lifted and service at the shopping centre has resumed.
Polcie have thanked the members of the public and the affected businesses for their patience and understanding while we dealt with the incident.
A police spokesperson said:
The safety of all concerned was our main priority.
We are treating the call as malicious and an investigation is underway to find out who was responsible.
Anyone with any information is asked to call North Yorkshire Police. Dial 101, press option 1 and pass information on to the Force Control Room.
Alternatively, Crimestoppers can be contacted anonymously on 0800 555 111.
Please quote reference number NYP-12082015-0119 when passing on information about the incident.