The needles were found in sandwiches on four US-bound flights from Amsterdam. Two of the flights were bound for Atlanta and the other two for Minneapolis and Seattle.
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The character's death will send shockwaves through Weatherfield.
It reportedly threatened attacks on planes "flying from Heathrow to the US" across the July 4 US Independence Day holiday weekend.
Accompanied by the Duke of Edinburgh, the Queen will attend the opening ceremony of the fifth session in the Holyrood chamber.