Manchester Bombing: The Latest on the Ariana Grande Concert Attack

Updated | The latest victim of the Manchester suicide bomb attack that killed 22 and left 63 wounded has been named by his family as 29-year-old Martyn Hett.

His family has said on Twitter they were "heartbroken" to discover Martyn was among those killed in the terror attack.

"They found my brother last night. We are heartbroken," his brother Dan posted on the social media site Wednesday. A friend described Hett from Stockport as "iconic."

"We got the news last night that our wonderful iconic and beautiful Martyn didn't survive. He left this world exactly how he lived, centre of attention," Russell Hayward said, also on Twitter.

Greater Manchester Police have said an off-duty police officer was killed in the bomb blast but did not disclose her name. The officer and her husband and two children were injured in the explosion. His condition was said to be critical.

In the early hours of Wednesday morning, 15-year-old Olivia Campbell was also identified as one of the dead. Writing on the Twitter, one of the teenager's friends, Aleshia Anne, asked for the the Campbell family's privacy to be respected.

Writing on the social media platform Twitter, one of the teenager's friends, Aleshia Anne, asked for the the Campbell family's privacy to be respected.

"Unfortunately, I can confirm Olivia Campbell was one of the angels taken too soon. Currently sat with her mum and step dad," she said in one tweet.

"We just ask everyone to be respectful at this time and continue to look for the ones that are still missing. Rest in peace Oli," she added in a separate message posted in the early hours of Wednesday morning.

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Olivia's mother Charlotte earlier made a television appeal urging members of the public to come forward if they had any information about her daughter's whereabouts when she did not return from the concert on Monday night.

Writing on Facebook the 36-year-old said the family's worst fears had been realised: "RIP my darling precious gorgeous girl Olivia Campbell taken far far to soon go sing with the angels and keep smiling mummy loves you so much."

Gorgina Callander, 18, was the first person confirmed as dead after the deadly blast at the Manchester Arena. In a statement released by Runshaw Sixth Form College, the teenager's school said: "Our deepest sympathies, thoughts and prayers go out to all of Georgina's family, friends, and all of those affected by this loss."

Early Tuesday, Manchester Police confirmed many of the 22 killed by the Manchester Arena blast were children. Speaking after an emergency Cabinet meeting, British Prime Minister Theresa May said the attack stood out for its "appalling, sickening cowardice, deliberately targeting innocent, defenceless children and young people, who should have been enjoying one of the most memorable nights of their lives."

The youngest and the second of the victims named following the attack late Monday evening was 8-year-old Saffie Rose Roussos. Her school, Tarleton Community Primary School released a statement following her death. The head teacher Chris Upton said: "Saffie was simply a beautiful little girl in every aspect of the word. She was loved by everyone."

The Polish government has confirmed two Polish nationals, identified in the British press as Marcin and Angelika Klis, were killed in the attack as they arrived to pick up their children.

"The parents came after the concert to collect their daughters and unfortunately we have information that they are dead. The children are safe," Polish foreign minister Witold Waszczykowski told private radio RMF FM, according to Reuters.

John Atkinson, 26, was named as the third victim of Monday's attack by the Manchester Evening News. Family members and friends posted tributes to him on social media. Further details were not immediately available, though a GoFundMe page was quickly established in Atkinson's memory.

Local politician Ivan Lewis tweeted that his thoughts and prayers were with Atkinson's loved ones. "Our Radcliffe community will do all we can to support John's family," he added.

The death of Kelly Brewster was confirmed on Facebook by her partner Ian Winslow, who wrote in a simple online statement, "Not sure how this works but it isn't good news. Kelly Brewster wasn't one of the unidentified hospital patients. She has sadly passed away in the terror attack yesterday."

The Sheffield Star reported Brewster had died while shielding her niece and sister from the bomb blast. She was described as a "hero" in online tributes.

The Daily Telegraph reported Alison Howe, 45, and Lisa Lees, 47, from Royton, Oldham, were killed as they were waiting together in the foyer of the arena."

Lees's brother, Lee Hunter wrote on Facebook : "For those who don't know Lisa is gone but never, ever forgotten. I love you Lisa I'll miss you so much." Howe's stepson Jordan Howe wrote tributes to his stepmother on Facebook, saying: "They took a caring beautiful mum and step mother away from us all she was amazing to us all."