Afghan officials say the twoWesterners were gunned down as they sat in a vehicle in front of theGerman-owned freight company DHL.
On the scene, General MirzaMohammad Yarmand, the director of the Interior Ministry's criminalinvestigation department, told reporters the shots were fired frominside the DHL office.
General Yarmand says one of the guards atthe DHL facility fired at the vehicle, killing the two foreign companyofficials and their Afghan bodyguard. He says a motive has not beenestablished.
The DHL office is located at a busy intersection across from the Iranian Embassy, in an upscale section of Kabul.
Police and diplomats say the two DHL officials - the country director and deputy director -- were from Britain and South Africa.
Officialsof Saladin, a British-based private security company confirmed to VOANews that the Afghan guard who died was employed by them.
Authorities say two other Afghans, standing outside the DHL office, were wounded in the shooting.
Policedetained 13 people, including DHL employees and guards. InteriorMinistry officials say they are questioning them to determine whetherthe shooting stemmed from an "internal dispute" or outsiders wereinvolved.
The latest violence comes less than a week after theshooting death of Gayle Williams, a British-South African nationalworking for a Christian charity in Kabul. Taliban insurgents claimedthey attacked the young woman because her British organization, SERVEAfghanistan, was spreading Christianity.
The charity denied it was proselytizing but decided to close its operation in the country following the killing.
Securityhas deteriorated in the capital and many parts of the country. Talibaninsurgents and criminal gangs are blamed for a recent wave of killingsand kidnappings targeting Afghans and foreigners.
Afghanauthorities say several foreigners have been abducted in the past fewdays in the country. Among them are two Bangladeshi development workersin Ghazni province and two Turkish engineers hired to erect acommunications tower near the Pakistani border in Khost province.