Gunmen on motorcycles shot dead five female airport workers and their driver in southern Afghanistan on Saturday, underlining the dangers facing employed women in the conservative, conflict-torn country.

The women, employees of a private company that provides luggage and body search services for female passengers, were in a van driving to the airport in Kandahar when three gunmen opened fire at them.

"All the women and their driver aboard the van were killed. The attackers fled the area and we have launched an investigation," provincial spokesman Samim Kheplwak told AFP.

The women had been concerned about their security after receiving death threats from people who disapproved of their career, Kandahar airport director Ahmadullah Faizi said.

Taliban militants who implemented a harsh version of Sharia law during their 1996-2001 rule, not allowing women to work outside their homes, said they were not behind the killings.

But employed women have long faced a high risk of attacks from insurgent groups and conservative Islamists.

Afghan President Ashraf Ghani said the killing of innocent civilians and women showed the "weakness of the enemies of Afghanistan".

The United Nations also condemned the killings and called for a "prompt, effective, impartial and transparent investigation" into the incident.

Afghan women have made giant strides since the Taliban regime was ousted in 2001, but they are still absent from public life and continue to suffer high levels of violence, oppression and abuse.

The Afghan attorney general's office recorded more than 3,700 cases of violence against women in the first eight months of 2016, with 5,000 cases recorded in the whole of the previous year.

In October last year, unidentified gunmen on a motorcycle shot dead a woman working as a rights defender with the UN in Kandahar.

And in 2013, a top female police officer was shot dead in neighbouring Helmand province as she was travelling to work. Negar, who had been in the police for five years, worked as a sub-inspector in the elite criminal investigation department in Lashkar Gah city.