Foreign Minister Julie Bishop has announced two Australians were among the seven people killed in last weekend's attack on London Bridge and the nearby Borough Market.
The family of 28 year-old South Australian woman Kirsty Boden has confirmed she is one of the victims.
Ms Boden was working as a nurse at a nearby hospital, and witnesses say, after the van and stabbing attack began, she ran towards the scene to try to help.
Her family has released a statement praising her courage and selflessness.
It says, in part:
"We are so proud of Kirsty's brave actions, which demonstrate how selfless, caring and heroic she was, not only on that night but through all of her life. Kirsty, we love you, and we will miss you dearly."
It was not immediately clear whether Ms Boden was hurt when three men used a van to run down pedestrians on the bridge or when they then went on a stabbing rampage.
The family statement describes her as "the most outgoing, kind and generous person, who loved to help people."
A 21 year-old Brisbane woman, Sara Zelenak, has been missing since getting separated from friends on London Bridge during the attack.
Ms Zelenak, working as an au pair in the city, had been given the night off.
Her family has been reported to be distraught and "bracing for the worst."
Her mother, Julie Wallace, says the last time she spoke with her daughter, she was looking forward to an upcoming family trip to Paris.
"Very smart, sensible girl. The last time I spoke to her was our time Friday afternoon, 4:20, 4:42 Friday afternoon, and she said, 'Oh, Mum, it's only 28 days until you and I and Dad can have baguettes and cheese and croissants in Paris.'"
A Facebook post by a family friend, shared hundred of times, appealed for information about Mz Zelenak, saying she usually called her mother daily.
The three men involved in the attack have now been identified, and the emergence of more details about them has led to accusations of warnings and missed, telltale signs.
Prosecutors in Italy, where the mother of one of the men, Youssef Zaghba, lives, say they stopped him at Bologna (bo-LON-yuh) airport last year when he was trying to fly to Turkey.
The Bologna prosecutor has told a local radio station Zaghba aroused suspicion because he was travelling with a backpack.
He also allegedly told the check-in agent he wanted to be a terrorist before quickly correcting himself.
Many militants have used Turkey as an entry point into IS-controlled areas of Syria.
Without proof of a crime, officials returned his belongings and alerted London authorities to his presence there.
A relative of the man says he went to London to find a job.
"He went to London. He was away for two or three months, then he came back. He was here for a month, and then he told his mum, 'I'm leaving, because, here, there's nothing and, in London, I can work.'"
Italian media say Zaghba was born in the Moroccan city of Fez and had cut off contact with his Moroccan father.
He was allegedly working in a London restaurant at the time of the attack.
British police say neither they nor the domestic-intelligence agency MI5 had investigated the 22-year-old before the attack.
Meanwhile, speaking at a campaign event, Britain's Prime Minister Theresa May has promised to change the nation's human-rights laws if they block her moves to fight terrorism.
"Let me just tell you a little bit about what I mean by that. I mean longer prison sentences for those convicted of terrorist offences. I mean making it easier for the authorities to deport foreign terrorist suspects back to their own countries. And I mean doing more to restrict the freedom and movements of terrorist suspects when we have enough evidence to know they are a threat but not enough evidence to prosecute them in full in court. And if ... if our human-rights laws stop us from doing it, we'll change those laws so we can do it."
