London, Sep 28 (IANS) A woman angry about separation from her ex-boyfriend triggered a bomb threat on a Pakistan International Airlines plane and forced the aircraft to make an emergency landing in Sweden, it was revealed Monday.

The woman called Canadian police to tell them that a flight from Toronto to Karachi had a bomb on board. The plane made an emergency landing in Stockholm Saturday, where Swedish police evacuated 273 passengers and arrested the woman's ex-boyfriend.

The 28-year-old Canadian man was later released without charge after no explosives were found on the plane.

He was on his way to Pakistan to get married and his ex-lover called police because she was angry about their separation, Britain's Daily Mail reported citing Swedish newspaper Aftonbladet.

"An ex came forward with the claim in connection with their separation. It was surely not a happy one," Stockholm police officer Haakan Westing, told the Swedish paper.

"She had an evil eye on him," he added.

The Royal Canadian Mounted Police said they were investigating whether the incident was a "terrorism hoax".

Spokesman Sergeant Marc LaPorte said an anonymous caller rang twice claiming a man on the flight had explosives.

"We take any call of this nature very seriously," he said.

"We have to ascertain the credibility and reliability of the call and try to determine whether there was a deliberate intent on behalf of the caller to mislead the police or if it falls into the definition of a terrorism hoax."

The jet flew to Manchester Sunday, where a new crew was due to board the aircraft for the rest of its journey to Karachi. The plane reached its final destination Monday.