Police are treating an explosion at Manchester Arena as a terrorist attack.

Here is how events unfolded at the city concert venue.

:: Monday, 6pm: Doors open at Manchester Arena in the north of the city centre. US pop singer Ariana Grande is on the bill for a sell-out concert at the 21,000-capacity venue. Fans, many of them teenage girls, excitedly share selfies as they wait for the show to begin.

:: 7.30pm: Show's scheduled start time. After a performance from support act BIA, an American rapper, Grande takes the stage.

:: 10.30pm Show's scheduled finish. Thousands of fans begin to file out of the arena's four exits.

A "huge bomb-like bang" is heard at the arena. Witnesses describe being knocked from their feet by an explosion and seeing dozens of injured, possibly dead, people including children lying on the floor. Others describe panic as concert-goers run for exits.

:: 10.35pm: Greater Manchester Police (GMP) are called to reports of an explosion at Manchester Arena. Dozens of emergency services vehicles stream into the area.

:: 10.55pm: Police urge people to stay away from the area as responders deal with a "serious incident".

:: 11.46pm: Police say there have been a number of confirmed fatalities.

:: Tuesday, 1.10am: Nineteen people are confirmed dead and around 50 others injured following the suspected explosion police say is being treated as a terrorist incident.

:: 1.35am: A controlled explosion is carried out on a suspicious item in the Cathedral Gardens area near Manchester Arena. It is later confirmed to be abandoned clothing.

:: 2.15am Prime Minister Theresa May says her thoughts are with the victims and families of those affected in "what is being treated by the police as an appalling terrorist attack".