Dr Chris Brown has joined the chorus of Australian and global celebrities paying tribute to the victims of Sunday's Bondi Beach terror attack that left 16 people dead.

The shocking attack at the iconic tourist destination unfolded as hundreds gathered to attend an event to mark the first day of Hanukkah.

Two heavily armed men, allegedly Naveed Akram, 24, and his father, Sajid Akram, 50, stood on a pedestrian footbridge and opened fire with military-grade weapons at crowds of locals, holidaymakers and families.

In the wake of the tragedy, Dr Chris, 47, best known as the star of the long-running Network Ten series Bondi Vet, took to Instagram to express his shock. 

Posting an image that showed a full moon rising over Bondi Beach, the celebrity vet admitted he was struggling to come to grips with how the 'peaceful' Bondi community had been shattered.   

'I'm still in disbelief. It's a tragedy that's so unfathomable for this community that's all about shared moments of joy… and peace,' Dr Chris wrote.

'This here, this is the Bondi I know.'

He added that the tragedy hit particularly close to home, given that he used to live across from the now infamous footbridge from which the two gunmen launched their attack.

Also the Bondi Junction Veterinary Hospital, where Dr Chris filmed Bondi Vet, is located just ten minutes from the site of the tragedy. 

'For years I lived across the road from that foot bridge that's now so synonymous with this tragedy,' Dr Chris continued.

'It was always a gateway to the tranquillity of the ocean and that beautiful sense of community that will also help Bondi get through this… somehow.'

He concluded his post by offering his sympathies to the victims and praising the bravery of Ahmed Al Ahmed, the hero who disarmed one of the attackers.

'Sending love to everyone affected. And thanks to everyone that helped and showed incredible courage. Like legendary Ahmed Al Ahmed. We are all with you,' he wrote.

The post was met with an outpouring of condolences from friends and followers from around the world.

'We are shocked and heartbroken. Sending love from Germany,' one offered, while a second added: 'Kia Kaha. Christchurch stands with you.'

A third wrote: 'Praying for comfort and healing in this time of mourning. This happens in the US too many times and we don't think of it happening in other countries.'

Bondi locals also shared how they, too, were still in disbelief over the shocking attack.

'I remember running across that bridge years ago barefoot because it was a million degrees, and even that small memory of once being where this took place has me shook. Just unbelievable,' one wrote. 

Dr Chris' comments come after celebrities from Australia and across the globe shared their heartbreak over the sickening attack.

The likes of Oprah Winfrey, who was recently in Australia on a speaking tour, Ashton Kutcher, Sacha Baron Cohen and Rebel Wilson took to social media in the wake of the tragedy.

'I just spent the last two weeks in Australia, walking Bondi just days ago feeling the openness and ease that lives there,' Oprah wrote on Instagram.

'It's hard to reconcile that sense of peace with the terror of last night. My heart breaks for the victims, their families and the loved ones, and all you Aussies.'

The death toll from the Bondi Beach massacre has risen to 16, and includes a child, marking one of the darkest days in the country's history.

NSW Police Commissioner Mal Lanyon also confirmed at least 29 people had been injured.

One of the gunmen, Sajid Akram, was also shot dead while the second, Naveed Akram, is in hospital under police guard.