Canadian police are investigating whether a phoned-in hoax caused a Pakistani jet to be diverted to Stockholm for several hours for fear that one of its passengers was carrying explosives.
Police evacuated 273 people from the jet, and briefly detained a Canadian man, after an anonymous caller in Canada tipped off authorities that the suspect was carrying explosives.
However, no explosives were found on the man, who was released after questioning by police, or on the Boeing 777 from Pakistan International Airlines, which had been bound from Toronto to Karachi, Pakistan.
The Royal Canadian Mounted Police said it is investigating whether the incident was a "terrorism hoax".
"If the information is deemed to be a hoax, the person who passed along that information can be charged for public mischief," said spokeswoman Sgt Julie Gagnon in Ottawa.
All passengers - except the suspect - were allowed back on the plane at Stockholm's Arlanda airport nine hours later.
It took off for Manchester from where the passengers would continue their journey to Karachi, said Jan Lindqvist, a spokesman for airport operator Swedavia.
Swedish police described the suspect as a Canadian citizen born in 1982. Initially they said he was of Pakistani background but later said they were not sure.
A spokesman for the state-owned Pakistan International Airlines said the suspect was a 25-year-old Canadian national.
A prosecutor decided to release the man after questioning, and police were trying to help him continue his journey to Karachi, police spokesman Erik Widstrand said, adding the man had co-operated with investigators.