A man shot dead his ex-girlfriend and another man before shooting himself dead in Vredenburg, Western Cape police said on Friday.

Inspector November Filander said three employees of the Saldanha Bay Municipality's housing office, two men and a woman, were walking out from their workplace on Thursday afternoon when they came across the woman's ex-boyfriend.

The ex-boyfriend, identified as Franco Jansen, 29, from Atlantis, walked with the group, which included his ex-girlfriend Washiela Julies, Roderick Pretorius and an unidentified 40-year-old man, to a vehicle outside.

Shortly after the vehicle pulled away, Jansen, who was seated behind the driver Pretorius, drew out a firearm and pointed it at him before ordering him to drive towards Paternoster, said Filander.

Pretorius spotted some of his other colleagues in front of a municipal head office on Main Road in Vredenburg and stopped the vehicle.

Jansen then shot Pretorius in the head before turning to Julies, who was sitting next to him in the back seat, and shot her in the head as well.

Jansen fired a shot in the direction of the 40-year-old man, who was sitting on the front passenger seat, but missed and the man escaped without harm. Jansen then turned the gun on himself.

Jansen, who had a gunshot wound to his head, and Pretorius were taken to Vredenburg Provincial Hospital, where they later died.

Julies, who was taken to the West Coast Private Hospital in Vredenburg, died on Friday morning.

A case of a double murder and an inquest were opened for investigation.

The firearm used in the incident was confiscated on scene.