Ed Sheeran, Niall Horan, Bruno Mars, Katy Perry, Demi Lovato and Harry Styles are among celebrities who have shared tributes for the people who were killed in the terrorist attack at an Ariana Grande concert in Manchester on Monday.

Twenty-two people were killed and dozens wounded in an explosion at the end of a concert by the 23-year-old US singer. 

British police say the attack was carried out by one man who died at the arena. The attacker was carrying a device which he detonated.

Musicians and celebrities have taken to Twitter in their droves to offer their condolences to the families of those who lost their lives in the tragic attack and to support the injured.

Grande, who brought her Dangerous Woman Tour to Dublin's 3Arena on Saturday, had been in the middle of her European shows, with gigs also scheduled in Belgium, Poland, Germany, Switzerland, France, Portugal, Spain and Italy. It has been reported by US celebrity magazine People that the singer is now back home in Florida.

A few hours after the explosion, Grande tweeted that she was "broken. From the bottom of my heart, I am so so sorry. don't have words."

"We mourn the lives of children and loved ones taken by this cowardly act," Scooter Braun, Grande's manager, said in a statement.

Ed Sheeran described the attack as "so heartbreaking" and sent "love and prayers".

"Absolutely Horrendous what happened in Manchester tonight. My thoughts are with the great people of Manchester and also Ari and her team xx," Mullingar singer Niall Horan said.

Boyzone star Ronan Keating tweeted about the "terrible news", saying "his thoughts are with everyone involved".

"I don't wanna believe that the world we live in could be so cruel," Bruno Mars wrote on social media.

"I'm heartbroken over what happened in Manchester tonight," One Direction star-turned-solo artist Harry Styles posted.

"Tearing up imagining innocent concert goers losing their lives," wrote Demi Lovato.

More artists expressed shock and sadness over the tragic events that unfolded leading to multiple deaths, including children who were attending the pop star's concert.

James Corden opened The Late Late Show on Monday night addressing the people of Manchester after the attack. "It shocks me every time we hear this sort of news, that attacks like this can happen, and especially when there will be so many children at this concert tonight," he said.