Family and friends share tributes to the Bourke Street car attack victims.

Five people have lost their lives, and many more are being treated for injuries, after a car sped along Bourke Street in Melbourne’s CBD after lunch time on Friday, ploughing into crowds of people.

Now, the families of two victims — Jess Mudie, 22, and Matthew Si, 33 — have remembered their lost loved ones in statements provided to Victoria Police.

Jess' family paid tribute to their "dearest and most badass daughter and sister," writing:

"You will always be a part of us and are one of the strongest people we know. We are constantly inspired by your love for everyone around you and the lengths you will go to for the people you love. We love your extravagant humour, the fact that you always laughed at your own jokes and your ridiculous names for everything like 'the guch'.

"You are always up to do everything and are such bright bubble of joy. Hydration is key, 'Remember me in the morning' is your cocktail of choice, and your personality ensures that will always be the case. You are strong, beautiful, determined, always work hard to get what you want and never shy away from a challenge. You always tell it like it is and if someone wanted the truth you would not be afraid to tell them.

"You are so headstrong and assertive in everything that you do, your love for your family and friends is immense, and you are always there when any one needs support... We love you so much."

Mr Si's wife, Melinda, said he was a devoted husband and a loving father, brother and son.

When the tragedy occurred, the pair had just parted ways to return to their respective offices after having lunch together in the city.

His "shattered" family wished to thank everyone who helped Mr Si at the scene and "did their best to save him".

Thalia Hakin, age 10, has been remembered as a "bubbly and bright" child by her loved ones. As the Herald Sun reports, one of her classmates said Thalia “was always happy and knew how to make people smile.”

The young girl's mother Nathalie and nine-year-old sister Maggie were also struck by the vehicle and sustained serious injuries; Thalia's father Tony is maintaining a bedside vigil for both.

“We all feel helpless and hopeless at times like this as there is so little we can do,” a family friend told the Herald Sun. A crowdfunding page has now been set up to raise money in support of the Hakin family.

The death toll of Friday's attack rose to five on Saturday evening, when it was confirmed a three-month-old baby boy had died.

According to the ABC, a 25-year-old man was also killed, while 37 people have been treated for injuries sustained in the rampage.

Four people remain in a critical condition, and there are fears the death toll will rise.