The victims, employed by Aircraft Charter Solutions/BalmOral (ACS/BalmOral), were killed in a suicide attack on a minibus taxi carrying foreign nationals.
The attack was carried out on Tuesday by a 22-year-old woman known only as Fatima.
According to the South African Press Association, the Afghan minibus driver, a ground crew member from Kyrgyzstan and a pedestrian also died in the attack.
The insurgent group Hizb-i-Islami has claimed responsibility for the attack, saying it was motivated by the recent anti-Islam film Innocence of Muslims.
A spokesperson for the group, Haroon Zarghoon, said the group considered all foreigners, whether military or civilian, as enemies.
"Foreign troops are fighting against Afghans and foreign civilians are tasked to spy for them. They all are our enemy and will be our target," Zarghoon told the Associated Press.
The presence of foreign forces in the country has drawn criticism from many quarters and has been blamed for continued violence in the country. On Wednesday the Claremont Main Road Mosque in Cape Town condemned the suicide bombing, but said the tragedy highlighted the need for US and Nato forces to "immediately cease its illegitimate war in Afghanistan".
A Johannesburg helicopter pilot told the New Age on Wednesday that while there was a lot of money to be made "very quickly" in Afghanistan, people working at the airport in Kabul were "sitting ducks for attacks".
The pilot, Clint Buckman, said airmen could earn at least R7 000 a day working in Afghanistan but he, himself, had returned shortly after arriving in the country because it was too dangerous.
A number of private aircraft charter companies operate in Afghanistan, where massive infrastructure development is being carried out by development and humanitarian agencies, often in remote areas that are hard to reach by road.
According to company spokesperson Candice Teubes the Johannesburg-based BalmOral, which has been in the aircraft charter industry for 18 years, works together with US-based "mother company" Aircraft Charter Solutions.
Lucrative charter business
A memo from the United States Agency for International Development (USAID), dated June 9 2011, shows that in 2010 USAid/Afghanistan awarded Aircraft Charter Solutions a $361-million two-year contract to supply passenger and cargo transportation in the region.
"The contractor is providing turnkey fixed-wing and rotary-wing aircraft, personnel, equipment, tools, material, maintenance, spare parts, and supervision necessary to provide air transportation between various locations in Afghanistan," it said.
At the time, the company provided seven 18-passenger Beechcraft 1900s, three eight-passenger Beechcraft Super King Air 200s, two Bell 412 helicopters, and four MI-8 helicopters.
It's believed about 120 South Africans work for ACS/BalmOral in Kabul, but Teubes could not confirm this.
According to the company website, BalmOral currently operates 16 aircraft in Afghanistan for various clients based at Kabul International Airport. Its clients include the World Food Programme. It has been involved in supporting both humanitarian aid organisations and peacekeeping operations, as well as oil, mining, construction and firefighting operations.
Dignity for the victims
The company released a statement on Tuesday saying it was deeply saddened by the deaths of its staff members and that it was in the process of notifying the next of kin.
"Our main focus now remains with the families of the innocent victims, who tragically lost their lives, our prayers and thoughts are with them, and all our staff remaining in Kabul," said the company in a statement.
Balmoral appealed for time to allow the families to grieve and requested the media respect the dignity of the victims and not publish pictures of their bodies.
The international relations and cooperation department, which has – since Tuesday – been working to identify the victims and notify the next of kin, said it would be releasing the names of the deceased later on Wednesday.
President Jacob Zuma released a short statement after the attack, saying he was deeply saddened by the deaths. "Our thoughts and prayers are with the families of the deceased," he said.