Manchester United says it will tighten security at its Old Trafford stadium after reports that 10 arrested terrorism suspects had tickets to a game this weekend.

Newspapers said the 10 detained under anti-terrorism laws on Monday in Manchester had tickets for seats scattered throughout the stadium for Saturday's match against Liverpool, and were planning to blow up the 67,000-seat venue.

"The plot involved several individual bombers in separate parts of the stadium," said the Sun.

Police have not commented on the reports and the club played them down, but issued a statement on Tuesday saying it is tightening security and calling for fans to be vigilant.

"In light of today's media reports...the club has consulted Greater Manchester Police. They have advised that Saturday's game and tonight's fixture against Charlton should proceed as planned.

"However, the club has decided that extra security checks will be made before kick-off which will inevitably lead to delays in getting into the stadium."

It asked fans not to bring bags and to stay vigilant.

Ten people, said by local media to be of North African and Iraqi Kurdish origin, were held in a series of raids involving 400 police across northern England on Monday.

Police said they were arrested "on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism" but declined to comment on whether they were believed to have targeted the soccer stadium.

An attack during a match between Manchester United and Liverpool -- one of the biggest games in the football calendar -- would have been broadcast live around the world. The clubs are third and fourth in the premiership.

Britain is on high alert for attacks after the Madrid train bombings which killed 191 people on March 11. London police chief Sir John Stevens has repeatedly said an attack, most likely a suicide bombing, is inevitable.