Prime Minister Malcolm Turnbull has characterised the deadly Manchester arena blasts as an attack on innocence.
"This incident, this attack, is especially vile, especially criminal, especially horrific because it appears to have been deliberately directed at teenagers," Mr Turnbull told parliament on Tuesday.
"This is an attack on innocence. Surely there is no crime more reprehensible than the murder of children."
"We stand in this chamber offering our sympathy and support to those confronting horrific attacks like what we've seen today," Mr Turnbull said.
"Australia stands with Britain in resolute solidarity - partners in freedom's cause."
What we know so far
Mr Turnbull has spoken to counter-terrorism co-ordinator Tony Sheehan, Australian High Commissioner in London Alexander Downer as well as the British high commissioner in Canberra.
UK agencies are treating the blasts as a potential terrorism event.
Labor leader Bill Shorten reflected on the pain of parents.
"You think when your kids go to listen to music, they would be safe. My eldest two are teenagers, they go to concerts," he told MPs.
"I can only begin to imagine the pain of parents wondering where their kids are when the first reports come out and the first texts and they realise that their family, their kids are at this concert."
He said his heart broke for those parents whose calls are being unanswered and the messages going through to that voicemail.
Foreign Minister Julie Bishop told reporters there was no information to suggest Australians were among the dead or injured in the "brutal" attack.
British High Commissioner Menna Rawlings told media in Canberra on Tuesday that the UK "remains a highly resilient nation".
Ms Rawlings said the UK would not be intimidated by terrorism. "Our values are freedom and liberty and democracy," she said.
Map: Manchester Arena and Victoria Station
Australian Olympic gold medallist Sally Pearson is staying at a nearby Manchester hotel in preparation for this week's Great North City Games in the city, but was unaffected by the blast.
"Terrible news for Manchester. Letting everyone know that I am safe over here and that my thoughts are with the Manchester community," Pearson tweeted.
* Australians concerned about friends or relatives in the UK should phone the Department of Foreign Affairs and Trade consular help line: 1300 555 135.
