Police in Manchester, England, confirm 19 people dead at Manchester Arena following an apparent explosion after a concert by Ariana Grande. About 50 people have been injured.
Authorities are treating the incident as a terrorist attack until they know otherwise, said Chief Constable Ian Hopkins of the Greater Manchester Police said in a brief early morning news conference.
Hopkins said police are working with national counterterrorism experts to investigate the explosion. He offered few details.
Prime Minister Theresa May will convene an emergency Cabinet meeting Tuesday. She released a statement saying, "We are working to establish the full details of what is being treated by the police as an appalling terrorist attack. All our thoughts are with the victims and the families of those who have been affected."
Ariana Grande tweeted: "broken. from the bottom of my heart, i am so so sorry. i don't have words."
Friends and relatives of the audience members who hadn't been heard from have posted messages on social media asking for word of their loved ones. Police have publicized a hotline number for families to call if they can't reach someone who was there.
Earlier, the police said they conducted a "precautionary controlled explosion," and the item they had been concerned about turned out to be abandoned clothing and not a suspicious item.
The management of the Manchester Arena issued a statement, saying the incident happened outside the facility.
The U.S. Department of Homeland Security said in a statement that it is closely monitoring the situation in Manchester and that it has "no information to indicate a specific credible threat involving music venues in the United States."
"However, the public may experience increased security in and around public places and events as officials take additional precautions," the statement said.
Reuters reports that emergency services are responding to the reports of "a serious incident." Greater Manchester Police are advising people to "avoid the area."
One witness, Josh Elliott, told the BBC Radio 5 Live that "A bang went off and everyone stopped and screamed. ... We basically hit the deck," he said. "It was bedlam ... it was horrific. We got up when we thought it was safe and got out as quickly as possible. People were just crying and in tears. ... Police cars were everywhere."
This is a developing story. Some things that get reported by the media will later turn out to be wrong. We will focus on reports from police officials and other authorities, credible news outlets and reporters who are at the scene. We will update as the situation develops.