Missing Aussie woman Sara Zelenak had two previous close calls with terror

Sara Zelenak is missing from Brisbane. She was caught up in the London terror attacks. Photo/Facebook/Sara Zelenak

The mother of Sara Zelenak, the Brisbane woman missing since the London attacks, has revealed her daughter had narrowly missed being on the scene in two previous terror incidents.

Julie Wallace spoke to radio station 97.3fm this morning and said she felt a sense of "terror" when she was told her daughter was missing.

"I have to go over there," she said.

"My boys are insanely distraught. We're a very close family, but I have to stay strong for them because that's what I've got to do."

Ms Wallace said her daughter had left for Europe in March and had already had a couple of close brushes with terror.

"The one with the policeman being stabbed three months ago, she was there the day before in the exact same spot," she said.

"She was going to go to the [Ariana Grande] concert. Everything she's just missed."

It is understood Ms Wallace has yet to fly to London as the search continues for the missing Australian.

Ms Wallace described her daughter as "very smart, sensible" and would not do "anything wrong in anyway".

"She's healthy, fit, trim, tall, terrific," she said.

Prime Minister Malcolm Turnbull confirmed an Australian 'named in the press today' was one of two citizens authorities had 'real concerns' for.

"We are working diligently in London with the police and other authorities there and of course, staying in very close contact with their families as we seek to confirm the circumstances relating to those two Australians," he told reporters in Canberra today.

A GoFundMe page raised a staggering $13,000 within 16 hours to help the family with the search.

Ms Zelenak was working as an au pair and Ms Wallace says her daughter had been given the night off so she could go out with a friend.

Sara Zelenak (right) was separated from friends during the attack. Photo/Facebook

"She was heading for the London Bridge where everyone goes on a Saturday night," Ms Wallace told Brisbane's 4KQ.

Ms Zelenak's friend Pri Goncalves says they became separated on the London Bridge when the attacks started.

"Sara was with me when people started running and shouting but at that very moment we got separated," she told Fairfax.

Ms Goncalves says she has been desperately trying to contact Sara since they were separated.

"When I was close to Borough Market I saw a guy on top of another guy who was screaming and then I knew something really bad was happening. I think he was stabbing him," she said.

"So I started calling her (Sara) but she never picked up the phone."

Friends of the Wallace family set up the GoFundMe page to "support them in their search for their missing daughter."

"She was last seen running from the terror attack during the horrific siege," they wrote.

"There has been no information to her whereabouts and we need funds to help with the search.

"There is a missing persons registration and everything is being done to locate Sara.

"The funds raised will be used to get her mum and dad from Australia to London and accommodate them while they continues to search for their beautiful daughter."

The fundraising page was set up yesterday and has already reached $13,152 of its $15,000 target in 16 hours.

Ondre Zelenak, the father of Sara Zelenak. Photo/Facebook

Ms Zelenak was meant to be babysitting before a last-minute change of plans put her right in the midst of the London terror attacks.

Ms Zelenak's heartbroken step-father Mark Wallace said his family hadn't heard from her for 48 hours and authorities hadn't been able to shed any light on where she was.

Desperate friends and family were on Monday night taking to social media to appeal for any information about the 21-year-old Brisbane woman's whereabouts.

Social media posts, which had been shared hundreds of times, said she was last seen on the London Bridge and had witnessed the attacks before becoming separated from friends.

"I feel terrible, I can't think," Mr Wallace said.

"Authorities in London can't give any information, they are in a terror lock down, so there's just no ability to find out or get any information... She's been gone for 48 hours and no one has seen or heard from her."

Mr Wallace said Sara's mother, Julie Wallace, was leaving Australia "first thing" in the morning to try and find her daughter in London.

Sara, a Moreton Bay College graduate, had moved to London in March to work as an au pair.

Mr Wallace said she had been planning to babysit the night of the attacks but at the last minute the children's grandma stepped in so she went out with friends.

"I've contacted every hospital in London," he said.

"I feel terrible, I don't know what my name is, I can't think.

"It's now been dragging out to be two days without knowing anything, and not knowing anything, it becomes quite difficult."

Sara Zelenak (left) was due home in August. Photo/Facebook

He said he and his wife had plans to meet up with Sara in France on June 29th and then she was expected to head back home to Australia in August.

Sara was not the type of person to be out of touch and she spoke with her family daily, Mr Wallace said.

"She would be in contact every day, it was constant communication," he said.

The family she had been staying with had filed a missing person's report and were also frantically trying to search for information, he said.

A Facebook post written by a family friend titled "Missing from London Terror Attack" has been shared hundreds of times.

This post read: "Dear friends please can I ask you to share this post. My friend's daughter, Sara Zelenak, was last seen on London Bridge and was witness to the terror attacks.

"She got separated from her friends and has not been seen since. Her phone has rang with no reply and now the battery must have gone.

"She is Australian aged 21 with long blonde hair. She calls her mum daily. It's been over 24 hours with no news from the consulate. We was hoping the 3rd Australian reported would be her, but it's not.

"She is based in London. Please share with as many people as possible especially if you have friends down south. Thank you for your help."

Sara's mother was meeting with Australian terror police in Brisbane on Monday night.