LONDON â A lone attacker blew himself up and killed 22 people, including children at a concert hall in the English city of Manchester said police Tuesday, adding it is being treated as a terrorist attack.
Police said that they were still trying to piece together what happened when the explosion ripped through a crowd of teenagers and other concertÂgoers late Monday after a performance by an American pop singer. At least 59 people were injured.
âWe have been treating this as a terrorist incident,â said Greater Manchester Police Chief Constable Ian Hopkins at a televised press conference. âWe believe at this stage the attack last night was conducted by one man.â
He said that the the priority was to establish whether he was working alone or as part of a network. More than 400 police officers have been deployed in the wake of the attack.
âThe attacker, I can confirm, died at the arena,â he said. âWe believe the attacker was carrying an improvised explosive device, which he detonated, causing this atrocity.â
Messages of support poured in from around the world, including from President Trump.
âWe stand in absolute solidarity with the people of the United Kingdom,â he said at a press conference in Bethlehem, and called those responsible âevil losers in life.â
The bombing appeared intended to inflict the maximum possible damage on young concertÂgoers â many of them in their early teens â who were making their way out of the Manchester Arena.Â Police said the blast occurred about 10:30 p.m., minutes after pop starÂ Ariana GrandeÂ had finished her set.
Â The explosion set off a panicked reaction as fans struggled to flee and parents and teens searched for one another amid the carnage. Well into Tuesday morning, fathers and mothers who had lost contact with their children posted desperate pleas for information on social media using the hashtag #ManchesterMissing.
Charlotte Campbell told the BBC on Tuesday morning that sheâs âphoning everybody,â including hospitals and centers trying to locate her 15-year-old daughter Olivia. She last spoke to her daughter on Monday night at the concert.
âSheâd just seen the support act and said she was having an amazing time, and thanking me for letting her go,â she said in an emotional interview.
British Prime Minister Theresa May issued a statement in the early hours of Tuesday sayingÂ that authorities were âworking to establish the full details of what is being treated by the police as an appalling terrorist attack.â
BBC reported that flags at the prime ministerâs residence on Downing Street were at half mast.
Andy Burnham, the mayor of Greater Manchester, called it an âevil actâ but praised the âspirit of Manchester that will prevail and hold us together.â
He said that Manchester is âgrieving today, but we are strong.â
There was no immediate claim of responsibility for the blast, and police did not speculate about possible motives.
If confirmed as a terrorist attack, it would be the worst strike on British soil since 2005, when Islamist extremists bombed the London subway and a bus,Â killing 54 people .
The U.S. Department of Homeland SecurityÂ said late MondayÂ that there was âno information to indicate a specific credible threat involving music venues in the United States,â but added that Americans may see âincreased securityÂ in and around public places and events as officials take additional precautions.â
In France, the scene of several terrorist attacks over the past year, French Prime Minister Edouard Philippe called on people to be vigilant in the face of âa threat which is more present than ever before.â
Britain has been onÂ high alertÂ for a major attack for several years, with authorities saying that a mass-casualty attack was likely.Â
Among the priorities for investigators will be to figure out whether itÂ was part of a broader plot.
Grande, who is wildly popular both in Britain and the United States, was not injured in the attack. She expressed herÂ sorrow in a tweet hours after the explosion, saying she was âbroken. from the bottom of my heart, i am so sorry. i donât have words.âÂ
Cellphone video showed chaotic scenes of people screaming and running in the aftermath of the blast. The arena was packed with attendees and pink balloons that had fallen from the ceiling during theÂ final song. Initially, concertÂgoers said they thought popping balloons had set off a panic, or that the screams were those of fans who had caught a glimpse ofÂ Grande.Â
But witnesses later reported seeing the prone bodies of those who had been wounded and killed, as well as others who were streaked with blood and were staggering away from the scene. Some were injured in the rush to get out, with people being trampled as thousands sought to Âescape.
In video of the moment that the explosion detonated, a concussive boom breaks through the chatter of fans heading for the exits. âOh my god, what just happened?â a female voice can be heard asking.Â âWhatâs going on?â
Later video showed people diving over railings. Concertgoers said that they saw nuts and bolts littering the ground near the blast scene and that the smell of explosives hungÂ in the air.
The local hospital, Wythenshawe, said it was dealing withÂ âmass casualties.â Five other hospitals across the city were activated to treat the injured, and emergency supplies of blood were rushed in.
Heavily armed police and emergency services swarmed the arena, withÂ ambulances â their blue lights flashing â rushing to the scene. The local emergency-
response service advised the public to call onlyÂ âfor life-threatening emergencies.â
Many of those attending the event were teenagers goingÂ toÂ their first concert. Witnesses reported that outside the arena, parents were frantically attempting to locate their children. Many parents and teens later gathered at a nearby Holiday Inn that was established as a meeting point.
Fans of Grande had come from across northern England to see the concert. On Twitter, people offered a place to stay for those stranded in the city, using the hashÂtagÂ #RoomForManchester.
ParentsÂ posted pictures of missing children on social media, pleading forÂ information. Police set up a hotline for those looking to connect with missing relatives.
A father told the BBC that he was leaving the arena with his wife and daughter when the blast blew him through a set of doors. Afterward, the man, identified as Andy, saidÂ he saw about 30 peopleÂ âscattered everywhere. Some of them looked dead.âÂ
Separated from his wife and daughter, he said, heÂ âlooked at some of the bodies trying to find my family.âÂ
He later found them, uninjured.
Other witnesses described a loud bang, followed by terrified shouts. âIt was really scary,â Michelle Sullivan, who was attending the concert with her 12- and 15-year-old daughters, told the BBC. âJust as the lights have gone down, we heard a really loud explosion. .â.â. Everybody screamed.â
âWhen we got out, they just said, âKeep on running, keep onÂ running.âââ
Karen Ford, a witness, told the BBC thatÂ âthere were kids outside, crying on the phone, trying to find their parents.âÂ
About 1:30 a.m., police announced that there would be a controlled explosion after a suspicious object was found. A loud bang was heard minutes later. Police later said the item that had been found was discarded clothing, not an explosive device.
The arena is one of the largest indoor venues in Europe and has a capacity of 21,000. Manchester transport police said the explosion occurred in the arenaâs foyer, where people were congregating to buy concert merchandise. Manchester Arena said the attack took place just outside the facility, in a public space.
Although nobody immediately asserted responsibility for Mondayâs violence, scenes of bloodied, panicked concertgoers running for safety brought to mind similar images at the Bataclan theater in Paris in November 2015.Â
The concert hall became theÂ scene of extreme carnageÂ after multiple gunmen burst in during a show by the American rock band Eagles of Death Metal and began shooting. The attack â for which the Islamic State later asserted responsibility â killed 89 people and injured hundreds more, becoming the deadliest event on French soil since World War II.
Britain has had fewer terrorist attacks in recent years than several of its European neighbors. Monday nightâs blast came two months after a speeding driver left four people dead on Londonâs Westminster Bridge, then stabbed to death a police officer at the gates of Parliament.
Monday was the fourth anniversary of the killing of Lee Rigby, a British soldier who was attacked with a machete on the streets of southeast London. The two assailants, who were convicted of murder, said they were acting to avenge the killing of Muslims by British soldiers.
Mondayâs blast comes with just over two weeks to go before Britain holds a national election. Campaigning was suspended Tuesday, and perhaps beyond. Security has not featured as a prominent part of the debate, although that mayÂ change when campaigningÂ resumes.
Grande is a 23-year-old pop singer and actress who has been in the public spotlight since 2010, when she began appearing on the Nickelodeon television show âVictorious.â More recently, the former teen idol has been touring to promote her third studio album, âDangerous Woman.â She has sold more than 1.7 million albums in recent years.
The singer has more than 45 million followers on Twitter. Grande is also one of the most popular people on Instagram, with 105 million followers â more than even BeyoncÃ©, Taylor Swift or Kim Kardashian. She was scheduled to play two shows in London later this week before traveling to Belgium, according to her tour dates.
Peter Holley and Devlin Barret contributed from Washington. Â