Ariana Grande Concert Bomber Found.

An apparent suicide bomber attacked an Ariana Grande concert as it ended Monday night, killing 22 people among a panicked crowd of young concertgoers, some still wearing the star’s trademark kitten ears and holding pink balloons as they fled.

Teenage screams filled the arena just after the explosion, which also killed the attacker and injured dozens.

The Islamic State terror group says one of its members carried out the attack, and police said Tuesday a 23-year-old man has been arrested in South Manchester in connection with the bombing. IS said “a soldier of the caliphate planted bombs in the middle of Crusaders gatherings” then detonated them, though police have only identified an "improvised explosive device" in the attack.

The United States’ top intelligence official says the U.S. government has not yet verified that the Islamic State group is responsible for the Manchester attack. Dan Coats, the director of national intelligence, told Congress that the extremist group frequently claims responsibility for terror attacks.

The attack sparked a nightlong search for loved ones — parents for the children they had accompanied or agreed to pick up, and friends for each other after groups were scattered by the blast. Twitter and Facebook were filled with appeals for the missing.

A police helicopter hummed over the city as somber commuters hurried to work. Public transport shut down, and taxis offered to give stranded people free rides home, while residents opened their homes to provide lodging.

The concert was attended by thousands of young music fans in northern England. 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.”

Police say they know the identity of the bomber but have not provided details yet.