Police were on Wednesday morning still searching for four armed men who shot and wounded two police officers during a routine stop on the M2 west highway.

During a stop-and-search operation, the four men, who were travelling in a silver Mercedes-Benz, opened fire on the officers.

Eyewitness News spoke to a man who witnessed the shootout.

The man, who did not want to be named, said he watched the drama unfold right in front of him.

He said a man in the passenger seat of the Mercedez-Benz stepped out of the vehicle with an R5 rifle and opened fire on the officers.

The witness said the incident happened quickly.

"Too many shots were fired... there were just too many to count," he said.

He added that although he was frightened, he could not stop watching the movie-like scene.

"I was very frightened. I heard the shots and got scared. But I kept watching."

Police spokesperson Lungelo Dlamini said they were following up on all leads to catch the four gunmen.

He said a manhunt had been launched and also appealed to the public for assistance. Both officers were airlifted to hospital, where one was in a stable condition and the other remained critical.