The car, a government vehicle, exploded near the Sanca intersection in the north of the capital.
"One person was killed in the blast, which destroyed a car belonging to the public works ministry," Muhidin Hassan Jurus, Yaqshid district commissioner told reporters, adding that the authorities were still investigating.
A local resident who saw the blast, Ali Mohamed, said it looked as if a device attached to the vehicle had exploded as it drove through the district.
The incident is similar to a car bomb on Wednesday that targeted a lawmaker's car in the capital and that killed one civilian and wounded several others.
No one has claimed this latest attack but al-Qaeda-linked Shebab insurgents have carried out a series of bombings, attacks and killings in a bid to overthrow the internationally backed government.
Despite recent fighting in the ranks of the Shebab and the loss of a series of towns they held to a 17,700-strong African union force, analysts warn that the extremist group is far from defeated.
