At least 22 people have been killed in what's being described by British police as a terrorist incident after an Ariana Grande concert on Monday night at the Manchester Arena.

Main developments:

  • At least 22 have been killed, children among the dead
  • Attack carried out by one man, according to police
  • Improvised explosive device used in what police have called a terrorist incident
  • Prime Minister Theresa May calls it an "appalling terrorist attack"

Credit: CNN