UPDATE: On Tuesday morning, British police confirmed 22 fatalities in the attack.

Police have confirmed 19 fatalities following reports of an explosion at Ariana Grande's concert in Manchester, U.K., on Monday night.

“Just before 10:35 p.m. on Monday, 22 May, police were called to reports of an explosion at Manchester Arena,” reads a statement posted by the Greater Manchester Police department on Twitter. “So far 19 people have been confirmed dead, with around 50 others injured. This is currently being treated as a terrorist incident until police know otherwise.”

A spokesperson for the star confirmed the “Love Me Harder” singer was not harmed.

“Ariana is OK. We are further investigating what happened,” a rep from her record label tells ET.

The concert reportedly ended around 10:30 p.m. local time, with the incident occurring between 10:40-10:45 p.m.

Concert-goer Holly Altman tells ET she was heading to the exit when the incident occurred after Grande's concert had just finished. “My parents saw like 30 bodies on the floor whilst waiting for me and my brother, but I was heading for the exit where the bomb went off,” she tells ET. “People turned and screamed and ran and then we ran out of there. I heard the police cars and ambulances, but I thought it was a gunshot to begin with.”

Police have not confirmed whether it was a bomb that caused the explosion.

Another eyewitness, Oliver, tells ET he was about 20 feet away from the incident. “The flames literally came through the doors,” he says. “Then it was just panic, people running, people falling, getting stood on. We could tell something wasn’t right immediately. We saw bodies on the floor but couldn’t tell if they were from being trampled in the rush to get out. [The explosion] was literally just when [the concert] finished about 10:40 p.m. and people were already in the area where the bomb exploded.”

A video posted on Twitter shows fans leaving Manchester Arena, where the 23-year-old pop star had just finished performing a concert as part of her Dangerous Woman tour. Screams can be heard in the background of the clip.

Further social media clips show chaos and panicking fans outside the venue and inside Manchester’s Victoria Station.

While Grande has not yet spoken out about the tragedy, fellow pop star Katy Perry paid tribute to those affected by the incident on Twitter.

“Praying for everyone at @ArianaGrande’s show,” she wrote.

Actor John Stamos also took to Twitter, confirming that he was in the area, but safe.

“We're on tour a half mile away from explosion but SAFE!” wrote the Fuller House star, who is currently touring with the Beach Boys. “Insane world. Grab all the peace and love you can. Praying now. #Manchester.”

Singers including Bruno Mars, Cher, Harry Styles and many more also expressed their shock on social media.    

Grande’s next concerts are scheduled for Thursday and Friday in London.