Unknown gunmen shot dead two foreigners and an Afghan in the heart of the capital Kabul on Saturday, police officials said.
Officials said they did not know the motive behind the attack, which comes amid rising violence in Afghanistan and less than a week after a woman British aid worker was killed in another part of Kabul.
Local media reports suggest there had been an argument between foreign and Afghan workers.
It was revealed both the Briton and the South African was an employee of the international courier company DHL, and the Afghani was a guard.
The shooting took place in front of the offices of DHL in the Sher Pur area where many foreign nationals live.
The Afghan Interior Minister, Mohammed Hanif Atmar, says witnesses have confirmed they were shot by an Afghan security guard, who later shot himself.
The British Foreign Office named the British man as David Giles.
