British military personnel will be used to protect key sites and events, as the UK raises is raising its terror threat level to 'critical' following the Manchester Arena terror attack.
Armed police on patrol in Manchester following the deadly terror attack. Photo: AFP
The attack at Manchester Arena after a concert by pop star Ariana Grande has left 22 people dead and more than 120 injured.
Prime Minister Theresa May said intelligence officials have advised that the threat level should be increased from severe to critical "for the time being".
"This means that their assessment is not only that an attack remains highly likely but that a further attack may be imminent."
British Prime Minister Theresa May, delivers a statement outside number 10 Downing Street in London. Photo: AFP
The prime minister said soldiers would be placed in key public locations to support armed police in protecting the public.
Military personnel may also be seen at other events over the coming weeks, such as concerts, Mrs May said, working under the command of police officers.
The prime minister said she did not want the public to feel "unduly alarmed" but said it was a "proportionate and sensible response".
Victims of attack named
So far three victims of the attack have been named - Saffie Rose Roussos, eight, Georgina Callander and John Atkinson, 28.
According to officials, 59 people are being treated at eight hospitals across the city.
Several have life-threatening injuries. 12 children under the age of 16 were still being treated and children were among the dead.
A further 60 people were being treated as 'walking wounded'.
- Read how it happened from our live blog or check a summary of the basics.
- Read the full report on the blast
Police earlier named Manchester-born Salman Abedi as the man suspected to have blown himself up, killing and injuring dozens of people at Manchester Arena.
Greater Manchester Police said the priority was to establish whether Abedi had worked alone or not.
Abedi is thought to have blown himself up in the arena's foyer shortly after 10.30pm on Monday, as fans were beginning to leave a concert by US singer Ariana Grande.
Abedi, who had at least three siblings, had lived at several addresses in Manchester, including a property at Elsmore Road, Fallowfield, which was earlier raided by police.
Police officers relocate floral tributes in St Ann's Square in Manchester following the attack at Manchester arena. Photo: AFP
Greater Manchester Police Chief Constable Ian Hopkins said searches at two addresses had been carried out, including the one in Fallowfield, where a controlled explosion had been used to gain "safe" access.
He said Abedi had not been formally identified by the coroner and so would not comment further.
Mr Hopkins passed on "heartfelt sympathies to all the innocent people caught up in last night's despicable act", adding that specially-trained family liaison officers were supporting families.
People congregate to attend a vigil in Albert Square in Manchester. Photo: AFP
"There has been much speculation and names of those who may have been killed in the media and social media," he said.
"We accept that this is inevitable, however, we ask that people allow the police and coroner to release the names once the families are ready and appropriately supported."
The Ministry of Foreign Affairs and Trade said there was no indication at this stage that any New Zealanders had been injured in the explosion.
The New Zealand High Commission in London is in contact with the local authorities, and are advising New Zealanders in Manchester to contact their family to confirm they are safe.
- BBC / RNZ