Police confirmed four people were killed and five others injured after a car loaded with explosives detonated along Maka Al-Mukarama road in the Somali capital, Mogadishu.
The director of a private ambulance service said his team collected 13 wounded people and one dead body.
Mohamed Abdikarin, a witness, said the blast was very huge, and he saw smoke and shrapnel everywhere around the area. Abdikarin added that police cordoned off the road and ambulances rushed to the scene to collect casualties.
The number of police checkpoints in Mogadishu has increased in recent weeks after a series of terrorist attacks.
In March, at least 30 people were killed in two separate attacks on a complex housing government ministries and a restaurant in Mogadishu.
Al- Shabaab fighters have been fighting for more than a decade in an attempt to dislodge the government.
