A woman was stabbed to death at a Pietermaritzburg mall on Monday, and her alleged attacker critically injured when he jumped off a bridge, KwaZulu-Natal police said.

The woman, 28, was stabbed twice at the Liberty Midlands Mall around 10am, Captain Thulani Zwane said.

Her alleged killer fled the scene on a motorbike, drove to a nearby bridge over the N3 and jumped onto the highway. He was critically injured.

Zwane said it was not yet known whether the two knew each other. The motive had not yet been established.

ER24 spokesman Russel Meiring said the man, in his late 20s, was found in the slow lane of the highway, surrounded by onlookers. He had severe back injuries.

"ER24 paramedics responded to the mall where a woman in her late 20s was lying in a large pool of blood. Two large wounds were visible on her neck."

Police, however, said the woman was stabbed twice in the chest. She died on the scene.

Zwane said the man was recovering in hospital under police guard and would appear in the Pietermaritzburg Magistrate's Court to face a murder charge when released.