The identity of the gunmen was unclear. Police in the coastal county of Kwale, where the Technical University of Mombasa (TUM) has a campus, said they could be robbers or militants.
Security is poor in the area and the convoy had a police escort. Somali Islamist militants al Shabaab frequently carry out attacks along the Kenyan coast and have been recruiting new members there.
In 2015, al Shabaab gunmen killed 148 students at a university in Kenya’s Garissa town near the Kenya-Somali border, an attack that provoked shock and outrage in Kenya and abroad.