A 58-year-old American man was arrested after airport officials found a "mock improvised explosive device" in a suitcase on a United Airlines flight bound for Chicago, Canadian police said on Thursday.

The device was swabbed for explosives and found not to be a threat to safety, a Peel Regional police spokesman said. The Chicago O'Hare-bound flight was delayed for hours from its scheduled 7 am EDT (1100 GMT) departure from Toronto.

The suspect, who was not identified, was held for a bail hearing on Friday.