A suspicious item discovered at the Old Trafford on Sunday was not a bomb but, in fact, a training device, the BBC reports.
Earlier on Sunday, the match between Manchester United and Bournemouth was called off after the suspicious device was found shortly before kick-off. Bomb disposal officers were called to the scene and carried out a controlled explosion.
Police said later the item had "accidentally" been left by a private company after a training exercise on Wednesday, according to the BBC. The Premier League match has been rescheduled for Tuesday.
Greater Manchester's Mayor and Police and Crime Commissioner Tony Lloyd called the situation "unacceptable" and said he wants an "urgent" inquiry to discover "how this happened, why it happened and who will be held accountable".
"This fiasco caused massive inconvenience to supporters who had come from far and wide to watch the match, wasted the time of huge numbers of police officers and the army's bomb squad, and unnecessarily put people in danger, as evacuating tens of thousands of people from a football stadium is not without risk," he said.
A Greater Manchester Police (GMP) statement quoted by the BBC read, "Shortly before today's planned football fixture, staff from the Manchester United ground alerted police to a suspicious item that had been found in the toilets within the North West Quadrant, between the Sir Alex Ferguson stand and the Stretford End.
"Police quickly attended and explosive experts were called in to assess the item, which has been described as an incredibly realistic-looking explosive device."
Assistant chief constable John O'Hare was quoted as having said, "I am grateful to the Manchester United and Bournemouth supporters for their support and assistance today.
"Following today's controlled explosion, we have since found out that the item was a training device which had accidentally been left by a private company following a training exercise involving explosive search dogs,” he added.
"While this item did not turn out to be a viable explosive, on appearance this device was as real as could be, and the decision to evacuate the stadium was the right thing to do, until we could be sure that people were not at risk."