Law enforcement officials were still combing the area.
Chief Superintendent Wayne Minnaar said the freeway was closed in both directions.
“Motorists are advised to use the N1, N3 and M2 as alternative routes.”
He could not confirm when the road would re-open.
A taxi driver was wounded when the police opened fire on him and his passenger following a chase from a Pretoria taxi rank.
The passenger fled when the taxi stopped near the Joe Slovo offramp in Killarney.
It was believed that he and the driver had been involved in several incidents relating to taxi violence.