LONDON — An explosion struck an Ariana Grande concert in northern England late Monday, killing at least 19 people and injuring dozens in what police say they are treating as a terrorist attack.
Greater Manchester Police said 19 people were confirmed dead and 59 were injured by the explosion at Manchester Arena. Emergency vehicles were helping the injured and bomb disposal units were later seen outside the venue.
There was mass panic after the explosion at the end of the concert, which was part of Grande’s The Dangerous Woman Tour. Grande, who was not injured, tweeted hours later: “Broken. From the bottom of my heart, I am so so sorry. I don’t have words.”
Britain’s terrorist threat level has been set at “severe” in recent years, indicating an attack is highly likely. Police said the explosion is being judged a terrorist attack unless new information proves otherwise.
Witnesses reported hearing two loud bangs coming from near the arena’s bars at about 10:35 p.m. but there were few further details.
“A huge bomb-like bang went off that hugely panicked everyone and we were all trying to flee the arena,” concertgoer Majid Khan, 22, told Britain’s Press Association. “It was one bang and essentially everyone from the other side of the arena where the bang was heard from suddenly came running towards us as they were trying to exit.”
Added Oliver Jones, 17: “The bang echoed around the foyer of the arena and people started to run.”
Video from inside the arena showed concertgoers screaming as they made their way out amid a sea of pink balloons.
British Prime Minister Theresa May said the government is working to establish “the full details of what is being treated by the police as an appalling terrorist attack.”
She said her thoughts are with the victims and the families of those who have been affected. The government is expected to call an emergency Cabinet meeting.
If the incident is confirmed as a terrorist attack, it would be the most deadly in Britain since the London subway bombings in 2005.
Police advised the public to avoid the area around the Manchester Arena, and the train station near the arena, Victoria Station, was evacuated and all trains canceled.
The Department of Homeland Security says there is no evidence of credible threats against music venues in the U.S. The department says the U.S. public may experience increased security in and around public places and events.
DHS says it is closely monitoring the situation at Manchester Arena and working with U.K. officials to obtain additional information about the cause of the explosion.
The government is urging U.S. citizens in Manchester to heed directions from local authorities and be vigilant about their security.
Anthony Guglielmi, a Chicago Police spokesman, said there was no known threat to Chicago following the attack.
“CPD is closely monitoring the incident in Manchester and we are in real-time communication with our federal partners,” Guglielmi said in a statement. “At this time, there is no nexus or known threat to the Chicago area but as always, we encourage individuals to report any suspicious activity to 911. Our thoughts and prayers go out to all of those affected by this horrible tragedy.”
A number of Manchester taxi services say they are offering free rides to people trapped by the incident. The service could also be used by people trying to get to local hospitals to look for loved ones.
In addition some city residents opened their homes to provide overnight lodging for people who were stranded by the shutdown in some train services because of the incident. City officials said the true spirit of Manchester was surfacing in the hours after the incident.
Frantic loved ones of young people missing after an explosion at an Ariana Grande concert have taken to Twitter and Instagram with their photos and pleas for help.
Many Manchester residents responded early Tuesday with offers of shelter and details on locations where displaced concert-goers had been taken in.
Grande, 23, true to her youthful fan base, is a social media phenomenon with 105 million followers on Instagram and 45.6 million followers on Twitter. Her fans, proud “Arianators,” were among those who took to Twitter with prayers and tears.
Fellow stars offered condolences as well.
Taylor Swift tweeted, “My thoughts, prayers and tears for all those affected by the Manchester tragedy tonight. I’m sending all my love.”
Ellie Goulding, Cher, fresh from a big night at the Billboard Awards, and Katy Perry were among others to tweet their support.
Joseph Carozza, a representative from Grande’s U.S. record label, said the singer is OK and they are investigating what happened.
The Dangerous Woman Tour is the third concert tour by Grande and supports her third studio album, “Dangerous Woman.”
Grande’s role as Cat Valentine on Nickelodeon’s high school sitcom “Victorious” propelled her to teen idol status, starting in 2010.
Grande, with her signature high ponytail, went on to also star in spinoffs that included “iCarly,” as she worked to develop her recording career.
The tour began in Phoenix in February. After Manchester, Grande was to perform at venues in Europe, including Belgium, Poland, Germany, Switzerland and France, with concerts in Latin America and Asia to follow.
AP Music Writer Mesfin Fekadu contributed to this story from Jersey City, New Jersey.