At least 22 people were killed and some 50 injured in an explosion at an Ariana Grande concert in Manchester, England, that was being treated as a terrorist incident, cops said.

The tragedy took place immediately after the singer’s performance Monday in the Manchester Arena, where local police said there were “a number of fatalities and others injured.”

“There were bodies everywhere,” an unnamed witness told BBC Radio. “I don’t know how I survived.”

The Greater Manchester Police Department released a statement on Twitter, saying “this is currently being treated as a terrorist incident until police know otherwise.” The department confirmed that at least 19 had been killed.

Law-enforcement officials told NBC that a single explosion took place outside the arena by the train station. The explosion was timed to go off at the end of the concert as people exited the venue, according to the network.

Concertgoers were shocked and traumatized.

“Ariana Grande had just gone behind the curtain and the lights came up when there was this massive bang and a big cloud of smoke,” a concert-goer told The Guardian.

“I saw five people with blood all down them,” another attendee said.

Police warned people to stay away from the area as they responded to a “serious incident.”

Video from the concert showed the panic as fans fled the crowded scene. Other images showed people injured, though it wasn’t clear whether they were hurt from being caught in the stampede to get out of the stadium.

A woman who lives across the street told The Guardian she heard a loud boom.

“The bang was so big I heard it from my room which is at the back of the apartment blocks,” Suzy Mitchell said.

Grande is OK, according to the singer’s record label.