It was confirmed to be an accidental leftover from a training exercise .
However , Manchester United 's home game against Bournemouth was postponed for a future date after Old Trafford was evacuated because of the discovery of a suspicious device , which was destroyed in a controlled explosion .
Manchester United was confirmed to be an accidental leftover from a training exercise .
However , Manchester United 's home game against Bournemouth was postponed for a future date after Old Trafford was evacuated because of the discovery of a suspicious device , which was destroyed in a controlled explosion .