Children were among the 22 people killed in a suicide attack after an Ariana Grande concert at Britain's Manchester Arena, police confirmed Tuesday.
Meanwhile, Manchester Police Chief Constable Ian Hopkins identified the suicide bomber responsible for the carnage as 22-year-old Salman Abedi and warned angry residents against any reprisals.
"We understand that feelings are very raw right now and people are looking for answers," he said. "We will not tolerate hate towards any parts of our community."
Police have also arrested a 23-year-old man in Manchester in connection with the attack, said Hopkins, who did not identify him.
Abedi had a British passport, sources told NBC News, but it was not immediately clear where he was born. He was killed when he detonated an improvised explosive device near one of the venue's exits at 10:33 p.m. local time Monday, authorities said.
While Hopkins did not identify any of the dead, 8-year-old Saffie Rose Roussos' death was confirmed by her school.
Some 59 other people were wounded, including some who suffered life-threatening injuries, officials said.
And thousands of grieving Manchester residents were expected to attend a vigil at 6 p.m. local time Tuesday to remember the dead.
ISIS claimed responsibility for the attack but neither US nor British officials have corroborated that.
The pop star's fan base is primarily girls and teenagers, so the venue was packed full of families.
The blast sparked a nightlong search for loved ones as frantic parents tried to locate their children, and groups of friends scattered by the explosion sought each other.