Manchester City and Manchester United have expressed their shock and sadness following an explosion at a concert in the city that left 22 people dead and 59 injured.
The blast happened at the end of a concert by American pop star Ariana Grande at the Manchester Arena in the city centre on Monday night.
United wrote on Twitter: "We are deeply shocked by last night's terrible events at the Manchester Arena. Our thoughts and prayers go out to all those affected."
We are deeply shocked by last night's terrible events at the Manchester Arena. Our thoughts and prayers go out to all those affected.
- Manchester United (@ManUtd) May 23, 2017
City tweeted: "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."
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 City (@ManCity) May 23, 2017
City also opened up the Etihad Stadium for people who needed help or assistance following the incident with many concert-goers stranded in Manchester.
The stadium was also used as a base for families trying to find people still missing after the attack.
Players from both teams also offered their thoughts and prayers on Twitter to those affected by the incident.
United winger Ashley Young expressed his dismay at the incident on Twitter.
Absolutely shocked to hear the news this morning. Thoughts with all that lost loved ones & prayers for those being treated in hospitals ������❤
- Ashley Young (@youngy18) May 23, 2017
Old Trafford defender Daley Blind added: "Can't believe what happened last night, My thoughts go out to all those affected."
Former United defender Rio Ferdinand said: "My thoughts & prayers are with all the families & friends affected by last nights attack in Manchester! #StandTogether."
City captain Vincent Kompany echoed the sentiments of his fellow professionals.
I would like to express my deepest condolences to the families of the victims. It's a sad day for the great city of Manchester. #Unity
- Vincent Kompany (@VincentKompany) May 22, 2017
England winger Raheem Sterling added: "Shocking events for this great city. My thoughts and prayers are with the families."
USWNT midfielder Carli Lloyd, who signed a short-term contract at Manchester City in February, wrote on Twitter: "Sickened by what has happened in Manchester. Thoughts go out to everyone. This is literally right around the corner from me. I am safe."
Former City boss Roberto Mancini said: "I'm sad to see other terrorism victims. My solidarity with all the people involved with the tragedy at the #ManchesterArena."
Ahead of United's Europa League final against Ajax in Stockholm on Wednesday, UEFA said in a statement: "There is currently no specific intelligence which might suggest that any of the UEFA Europa League Final activities in Stockholm may be the target of attacks.
"UEFA has been closely working with local authorities and the Swedish FA for many months and the terrorist risk had been taken into account since the very beginning of the project. Furthermore, a number of additional security measures were implemented following the attacks in Stockholm last April.
"Due to the tight security arrangements, UEFA urges fans to arrive at the stadium as early as possible, as detailed checks will be made at the entrances, resulting in potential delays in accessing the stadium."
UEFA president Aleksander Ceferin added: "I am deeply saddened by the horrible terrorist attack in Manchester last night. It shocks me that so many innocent people lost their lives and I would like to send my condolences to the families of those affected."