The rally on Saturday is expected to go ahead with the blessing of health authorities after organisers submitted a COVID-19 management plan.

Anyone attending has been asked to wear a face mask and has been told that social distancing will be enforced.

Recent changes to coronavirus density rules in SA, which now allow one person to every two square metres at large gatherings, should make it easier for protesters to abide by virus restrictions.

Organisers say the rally comes at a historic moment in the fight against systemic racism.

"In Australia, we see mining corporations destroying historic sites while Aboriginal communities are forced through the humiliation of cashless welfare," they said on Facebook.

"Other black and migrant communities also face over-policing, job discrimination and social inequality."

Police Commissioner Grant Stevens said police would deploy the level of resources deemed necessary.

"We will have that level of response that is sufficient to address any concerns we have in relation to ensuring the safety of the people," he said.

Last month, more than 5000 people attended the first Black Lives Matter rally in Adelaide with police praising the peaceful event.

Australian Associated Press