Meet the new $9m counter-terror cops protecting South Australia

From today, 48 new specially-trained police officers will be patrolling South Australian streets, ready to react to terrorist incidents.

Even in Rundle Mall in Adelaide, the heavily-armed officers were highly visible.

"This is a different look for South Australia police, it is not a step that's been taken lightly," Police Commissioner Grant Stevens said.

"It's a sad reality that we live in a world where there are people who wish to do us harm for whatever issues that motivate them."

The squad – known as the Security Response Section – will be pre-deployed to big events, and patrol at-risk locations in Adelaide like Rundle Mall, the Railway Station and Central Market.

"Terrorist-based activities, or radicalised people can act without any warning, so it is important we remain vigilant," Mr Stevens said.

As crowds return to South Australian events post-lockdown, authorities say there's no need to be alarmed at the sight of members of the new squad, as they will be routinely patrolling mass gatherings – including AFL games and large-scale protests.

It cost $9 million to set up the new team.

Squad members received specialist weapon training and bomb detection training.