Brisbane woman Sara Zelenak has been confirmed as the second Australian killed in the London terror attacks.

The 21-year-old’s mother Julie Wallace, who was flying to London in the hope to find her missing daughter, broke the tragic news on Facebook at about 3pm on Wednesday afternoon (AEST).

“Sara Zelenak is confirmed dead. They found her body and DNA tests have confirmed,” the post read.

“Thank you for all the overwhelming love and support from everyone.”

Ms Zelenak was separated from her friend on London Bridge when the violence began and was last seen fleeing the bridge.

Her aunt Tara told media yesterday the family was “bracing for the worst”.

Online tributes began pouring in from friends of Ms Zelenak as the news filtered through.

“Sara Zelenak you will be unbelievably missed! Sending my love to your family, friends and, of course, our Bay Girl family,” friend Jamie Ambrosi-Fitzpatrick wrote.

Another friend Sophie Clark posted: “Such a beautiful, fun soul. RIP beautiful girl, you will be dearly missed!”

Ms Zelenak’s friend Pri Goncalves told Fairfax Media earlier this week: “Sara was with me when people started running and shouting but at that very moment we got separated,”

Ms Zelenak had been given the night off working as an au pair to go out with a friend, and it was her host family who called the family back in Australia to tell them she had not come home.

She died ‘trying to save others’

Late on Tuesday, it was confirmed that South Australian nurse Kirsty Boden was also killed in the attack.

The Boden family said Kirsty, 28, was running to help victims of the stabbing and van attack when she was fatally injured.

“As she ran towards danger, in an effort to help people on the bridge, Kirsty sadly lost her life,” they said.

“We are so proud of Kirsty’s brave actions which demonstrate how selfless, caring and heroic she was, not only on that night, but throughout all of her life. Kirsty – we love you and we will miss you dearly.”

It was unclear if Ms Boden was hurt on the bridge or when the three men in the van went on a stabbing rampage in a nearby Borough Market.

The three terrorists were quickly shot dead by police.

Seven people were killed during the terror attack, during which several men drove a van into pedestrians on London Bridge before attacking others with knives near the Borough Market.