Lamu County Commissioner Irungu Macharia confirmed the incident, saying three occupants, who work for a private contractor at the Kenya-Somalia security border wall construction site, dubbed Usalama camp, were in the vehicle at the time of the incident, the Xinhua news agency reported.
"Two people died in the incident while one was injured. We strongly believe the improvised explosive device (IED) was planted by al-Shabab militants. Our security forces are currently pursuing them," the government official said.
The attack took place a few kilometers from Ishakani village in Kenya's coastal county of Lamu, just next to the border with Somalia.
This latest attack came barely a month after a water bowser heading to the Usalama camp ran over an IED believed to have been planted by al-Shabab militants, killing one person on March 23.
In 2015, Kenya began the construction of a 700-kilometre-long wall, dubbed the Kenya-Somalia border securitization project, to secure the country from attacks by the Somalia-based al-Shabab terrorists. The project plan includes having designated immigration and custom entry points with a two-feet-tall concrete wall fitted with CCTV cameras.