22 Killed in Bombing at Pop Concert in Britain, With Children Among Dead

MANCHESTER, England — The attack at a Manchester concert that left at least 22 people dead was almost certainly carried out by one person, the chief of the Manchester police said Tuesday morning, a bombing that shocked the country and underlined the continued threat to European security.

Ian Hopkins, the chief constable of the Greater Manchester Police, said the authorities were trying to determine whether the assailant, whose nationality he declined to identify, was working on his own or with assistance.

Chief Constable Hopkins said that the attack was being treated as a “terrorist incident” and that the assailant had died in the blast Monday night at Manchester Arena during a concert by the singer Ariana Grande. The singer has a large and international following, and her concerts are known for attracting a young crowd, including groups of teenage girls and their parents.

There were children among the dead. The authorities said 59 people were wounded in the attack, which appears to be the deadliest episode of terrorism in Britain since coordinated attacks on the London public transit network in 2005.