A Black Lives Matter rally billed to attract thousands in Sydney was shut down by NSW police before it began and its organiser Paddy Gibson was arrested.

Police said six people were arrested during the “unauthorised” public gathering in The Domain, which nearly 5000 people had registered on Facebook to attend.

It came to nothing as NSW Police ordered protesters to disperse 15 minutes before it was scheduled to begin on Tuesday at 12pm.

In what was described by police as a “high visibility police operation” which included officers from the public order and riot squad, they appeared to outnumber protesters at the park and six arrests were made.

Five of those people – three men aged 22, 37 and 40 and two women aged 23 and 50 –  were handed $1000 fines for breaching public health orders, while a third woman, 25, was arrested and handed an infringement notice for offensive language.

“We appreciate people’s right to protest. We understand the issues that are in question here are significant and are sensitive to a lot of people,” NSW Police Assistant Commissioner Mick Willing told reporters.

“However we must do what we can to ensure the public in general are safe.”

A protester is escorted from The Domain on Tuesday. Photo: ABC

In a statement, police said that the NSW Supreme Court had prohibited the public assembly planned for Sydney due to health and safety concerns associated with COVID-19.

Following an unsuccessful appeal application on Monday, the protest remained unauthorised. Despite this, police received information a number of people still planned to attend.

• Related: Plane passengers test positive to COVID-19
• Related: NSW pubs, restaurants close amid virus spread

Organiser Paddy Gibson, 37, was one of those arrested and said supporters were asked to gather in groups of fewer than 20 after failing on Monday to overturn a NSW Supreme Court decision prohibiting the protest.

Mr Gibson said organisers directed protesters to leave peacefully and without confronting police after being told mass arrests would otherwise occur.

Mr Gibson said he’d also been told by police that despite The Domain’s size, only 20 protesters would be permitted in the park.

“We weren’t allowed to give it a run even though Westfield is allowed, as well as the casino and the NRL,” Mr Gibson told AAP.

“People are allowed to come together to make profits but they’re not allowed to come together to say black lives matter; that’s a disgraceful situation in NSW.

“They don’t want to see us build unity, build power, demand accountability and demand justice from this government because it’s too politically sensitive.”

One of the six protesters arrested before the rally even started. Photo: AAP

Mr Gibson said protesters would challenge in court any fines handed out.

Justice Mark Ierace on Sunday accepted the possibility of community transmission of COVID-19 at the Sydney rally made the event too risky.

The appeal court on Monday dismissed a challenge to Justice Ierace’s decision.

Organisers previously said they would risk arrest and go ahead with the rally, before delivering a petition with some 90,000 signatures to NSW parliament calling for justice for Indigenous man David Dungay Jr.

Mr Dungay, 26, and a diabetic, died in December 2015 after five prison officers stormed his Sydney jail cell to stop him eating biscuits.

NSW Premier Gladys Berejiklian had earlier on Tuesday appealed to “people’s conscience and ethical standards” not to attend.

Black Lives Matter rallies have been held around the globe, sparked by the murder of US man George Floyd by police in Minneapolis on May 25.

Protesters at Tuesday’s rally in Sydney. Photo: ABC

Protesters headed to Hyde Park

The ABC reported several protesters headed to nearby Hyde Park but they did not congregate as police officers trailed them.

After the protesters were detained, a post on the event’s Facebook page, Justice For David Dungay Jnr, instructed people on the way to the march to stay away instead, the ABC reported.

“We are now appealing for people NOT to come to the Domain.

“Please share spread the word the rally is OVER.”

-with AAP