Wayne Rooney, Rio Ferdinand and Manchester United lead heartfelt tributes to victims of attack at Manchester Arena

[PHOTO: COURTESY]

Manchester United expressed the club's sympathy after an explosion in the city left 22 people dead.

The blast at the end of a concert by American pop star Ariana Grande at Manchester Arena has also left 59 people injured.

United's players are set to train on Tuesday before flying out to Stockholm for the Europa League final, with flags at Old Trafford at half-mast.

A message on the club's official Twitter account read: "We are deeply shocked by last night’s terrible events at the Manchester Arena. Our thoughts and prayers go out to all those affected."

Skipper Wayne Rooney paid tribute, alongside teammate Jesse Lingard and former defender Rio Ferdinand.

"I would like to express my deepest condolences to the families of the victims," City defender Vincent Kompany posted as information filtered from the scene.

"It's a sad day for the great city of Manchester. #Unity"

Man City's official Twitter profile said: "It's with great sadness we hear of the terrible events at the Arena. Our hearts go out to all affected and to our city's emergency services."

Manchester United are expected to wear black arm bands when they face Ajax in the Europa League final on Wednesday night in Sweden.

The Dutch giants also expressed their sympathies ahead of the encounter.

England's Under-20s also paid their own respects as their players wore black armbands for their match with Guinea.

The full might of Manchester's emergency services was deployed to the scene where a significant number of the 21,000 people who attended the concert were left with "shrapnel type injuries".

Match of the Day host Gary Lineker said: "Truly awful news from the great city of Manchester. Thoughts are with all those affected."

A host of Premier League clubs and sports stars also paid tributes to those affected.