The mayor of Manchester, Tony Lloyd, has called for an investigation into how a fake bomb used for training purposes was left in a stadium restroom at Old Trafford, where it prompted an evacuation of the stadium and a cancellation of Manchester United's final league match of the season.

“It is outrageous this situation arose, and a full inquiry is required to urgently find out how this happened, why it happened and who will be held accountable," Lloyd said in a statement on the Greater Manchester Police & Crime Commissioner website, a supervisory post that Lloyd also holds.

After the evacuation, which was prompted by a suspicious looking package in a stadium restroom, police determined that a training device had been left behind by a private security company, who had used it earlier in the week to conduct a training exercise.

The device was destroyed in a controlled explosion.

Calling the error a "fiasco," Lloyd said it was an inconvenience and waste of resources for fans, police, and the army's bomb squad, adding that it "unnecessarily put people in danger, as evacuating tens of thousands of people from a football stadium is not without risk."

Lloyd also praised the professionalism of police and team officials.

Manchester United's final Premier League game of the season against Bournemouth has been rescheduled for Tuesday.

mz/jil (AP, dpa)