22 people are dead, 59 have been injured
A total of 22 people have died. A further 59 have been injured.
The victims are being treated at eight hospitals across the city.
"This is the most horrific incident we have had to face in Greater Manchester and one that we hoped we would never see," Greater Manchester Police said.
"Families and many young people were out to enjoy a concert at the Manchester Arena and have lost their lives.
"Our thoughts are with those 22 victims that we now know have died, the 59 who are injured and their loved ones.
"We continue to do all we can to support them.:
An emergency number has been established for anyone who is concerned their loved ones may not have returned home - 0161 856 9400 or 0161 856 9900.
'No Irish citizens affected at this time' - DFA
Ireland's Minister for Foreign Affairs and Trade, Charlie Flanagan, has expressed his shock at last night’s explosion in Manchester.
"I am shocked and horrified by the large loss of life in Manchester last night and my thoughts and prayers are with those affected, and we stand by our nearest neighbour, the UK especially due to the strong links between our country and the city of Manchester," he said,
"The Consular Section of my Department, in conjunction with our Embassy in London is monitoring the situation and we are not at this time aware of any Irish citizens affected."
The Irish Embassy in London has opened a line for those concerned about Irish people in the city - 0207 235 2171 or 00353 408 2000.
Reports of an explosion
At 10.33pm on Monday, May 22, Greater Manchester Police were called to reports of an explosion at the Manchester Arena where an Ariana Grande concert was ending.
More than 240 calls came in.
More than 400 officers have been involved in the operation during the night.
A terror incident carried out by one man
Police are treating the incident as a terrorist incident. They believe the attack was carried out by one man. They are now trying to establish if he was acting alone or as part of a network.
The attacker died at the scene.
Police believe he was carrying an improvised explosive device which he detonated causing this atrocity.
Police are working with National counter Terrorist Policing Network and British Intelligence services to establish more details about the man who carried out the attack.
The area around Manchester Arena remains cordoned off
A large cordon remains in place around Manchester Arena and Victoria Train Station, which will be in place for some time.
The station remains closed as a forensic search is underway.
"Terrorists attempt to disrupt out lives and create district and fear in communities.
"We have a long history in Greater Manchester of communities standing together during difficult times," Greater Manchester Police said.
"In the coming days we will work closely with community leaders to address any issues. It is important to remain vigilant, but also to go about our daily lives."