The shooting apparently happened when two groups of protesters clashed.

Eye witnesses told the police one group wanted to loot the shops of foreign nationals while the second one sought to stop this, Lt-Col Lungelo Dlamini said on Thursday.

He said the man was rushed to Helen Joseph Hospital in Johannesburg in a critical condition.

Police were investigating a case of attempted murder.

Dlamini said police arrested 12 people on Wednesday during protests over service delivery.

"They will appear in the Randburg Magistrate's Court on Thursday to face charges of public violence," he said.

Dlamini said police had to stop a group of protesters from attacking a mall in Randburg.

Police were still keeping watch, he said.

Johannesburg metro police said protesters continued burning tyres in Beyers Naude Drive, resulting in the road being partially closed between Juice and Peter roads.

Chief Superintendent Wayne Minnaar said there was a heavy police presence and motorists were advised to avoid the area and use Malibongwe Drive and Hendrik Potgieter road as alternatives."

On Wednesday, protesters blocked Beyers Naude Drive with stones and rocks and threw stones at cars.