Updated

Confirmed details of the deadly explosion during an Ariana Grande concert at Manchester Arena on Monday:

  • At least 22 people were killed and as many 56 others were being treated at a total of eight hospitals across Manchester, police confirmed early Tuesday.
  • Police identified the killer as 22-year-old Salman Abedi. He was British, a European security official told The Associated Press.
  • The victims who died were as young as 8.
  • Police said they were treating the explosion as a "terrorist incident" until they know otherwise. Manchester police said they were working with national police and intelligence agencies to investigate.
  • Ariana Grande tweeted: "broken. from the bottom of my heart, i am so so sorry. i don't have words." She was not injured, a representative for the singer said.
  • The blast rang out in a "public space" outside the venue, according to arena officials.
  • "U.S. citizens in the area should heed direction from local authorities and maintain security awareness," the Department of Homeland Security announced, adding: "At this time, we have no information to indicate a specific credible threat involving music venues in the United States."
  • The concert was almost finished at the time, and guests had started to leave the arena.
  • Police said it appeared to be one explosion, not two, despite earlier reports from witnesses. The explosion unfolded around 10:35 p.m. local time.
  • Police urged people to avoid the area around Manchester Arena. The train station near the arena, Victoria Station, was evacuated and all trains canceled.
  • Prime Minister Theresa May said her thoughts were with the victims and the families of those affected.
  • Mayor Andy Burnham said people who needed places to stay could monitor the hashtag #RoomForManchester on Twitter.
  • Police conducted a controlled explosion to destroy what they considered a suspicious device, but they determined it was abandoned clothing.
  • Police said about 400 additional police were deployed overnight.

Fox News' Jake Gibson, Catherine Herridge and The Associated Press contributed to this report.