A message from the Queen for what she has labelled as an "act of barbarity".
"The whole nation has been shocked by the death and injury in Manchester last night of so many people, adults and children, who had just been enjoying a concert.
"I know I speak for everyone in expressing my deepest sympathy to all who have been affected by this dreadful event and especially to the families and friends of those who have died or were injured.
"I want to thank all the members of the emergency services, who have responded with such professionalism and care.
"And I would like to express my admiration for the way the people of Manchester have responded, with humanity and compassion, to this act of barbarity.
The Prince of Wales and Duchess of Cornwall have expressed their "most heartfelt sympathy" for the families and friends of the victims of the "truly dreadful" Manchester terrorist attack.
Charles and Camilla echoed the sentiments of the Queen's message following the atrocity, when the heir to the throne said in a statement they were "profoundly shocked" to learn about the attack on Monday night which killed 22 people and injured 59.
The victims were targeted by a suicide bomber who detonated an improvised explosive device as young fans left a pop concert by US singer Ariana Grande at Manchester Arena.
"My wife and I were so profoundly shocked to learn of the truly dreadful event which took place in Manchester last night," Charles said in his message of condolence.
"That such a large number of people, including so many young concert-goers, lost their lives or have suffered so much in this appalling atrocity is deeply distressing and fills us with intense sadness.
"Words cannot adequately express what so many families must be feeling at this incredibly difficult time and our most heartfelt sympathy is with all those who have so tragically lost loved ones or who have been affected in some way."
- AAP