Blast at Ariana Grande concert in England kills 19 people

LONDON (AP) — An explosion struck an Ariana Grande concert attended by thousands of young music fans in northern England late Monday, killing at least 19 people and injuring dozens in what police were treating as a terrorist attack.

Northwest Ambulance Service said 59 injured people had been taken to hospitals, and a number of "walking wounded" were treated at the scene.

Police cars, bomb-disposal units and 60 ambulances raced to the scene as the scale of the carnage became clear.

Britain's terrorist threat level stands at "severe," the second-highest rung on a five-point scale, meaning an attack is highly likely.

British Prime Minister Theresa May said the government was working to establish "the full details of what is being treated by the police as an appalling terrorist attack."

If the incident is confirmed as a terrorist attack it would be the deadliest in Britain since four suicide bombers killed 52 London commuters on three subway trains and a bus in July 2005.