A Premier League match between Manchester United and Bournemouth was abandoned on Sunday after a suspect package was found in the ground and an armybombdisposal unit was called.
The Alex Ferguson Stand and the Stretford End of the Old Trafford ground were evacuated about 20 minutes before the scheduled kickoff at 1400 GMT. Sniffer dogs were used to search the area.
"Due to a suspect package being found in the North West Quadrant, today's match has been abandoned on police advice," the club said on its website.
Greater Manchester Police said it was working with staff at the club to investigate a suspicious item found at the stadium.
"A controlled evacuation of the stadium has now taken place. We are awaiting the imminent arrival of military colleagues to come and support us and establish what exactly we are dealing with," Assistant Chief Constable John O'Hare said in a statement.
"We don’t make these decisions lightly and we have done this today to ensure the safety of all those attending."
Police also tweeted that the ArmyBombDisposal Unit were on the scene to help.
United are still in with a chance of clinching the final Champions League qualifying place, depending on Manchester City's result against Swansea City on Sunday.
They play Crystal Palace in the FA Cup final on Saturday and it is not clear when a rescheduled game against Bournemouth will be played.
In a statement posted on Twitter, the Premier League said it would seek to rearrange the fixture "as soon as practically possible".
"When it comes to matters of security it is obviously right that Manchester United and the Premier League place the safety of supporters and employees foremost," it said.
"It is always the last resort to abandon one of our fixtures."
A controlled explosion was carried out on a suspect package in Manchester United's Old Trafford ground on Sunday, police said.
Earlier a Premier League match between United and Bournemouth was abandoned and the stadium evacuated before kickoff following the discovery of the package.
"A controlled explosion has just been carried out within the stadium by bomb disposal experts at Old Trafford. More to follow," Greater Manchester Police said on Twitter.