Ride-hailing service Uber says one of its drivers in South Africa was killed in an attack.

Referring to the incident, South African police said Monday that a taxi driver was fatally shot while sitting in his vehicle in Cape Town at 5 a.m. Friday.

Police say no arrests have been made and they are trying to ascertain a motive.

Uber says in a statement that it has spoken to authorities, and that it appears there is no connection between the driver's death and the fact that he was working for Uber. It says it has been in touch with the driver's family to offer support.

In some countries, taxi drivers with other companies have protested against Uber, complaining of unfair competition.

South Africa has a high rate of violent crime.