Four people, including a prominent Somali businessman, were injured Thursday after a bomb went off in a vehicle in Somalia's capital Mogadishu, witnesses said.

The businessman, Hussein Goley, was in his car which was parked near Dahabshiil Bank, the main money transfer company in Mogadishu, when the bomb hidden inside the vehicle went off, setting the car on fire, witnesses said.

"The businessman parked his car and the bomb exploded and there was fire at the front part of the vehicle. Four people including Hussein Goley were injured. They were taken to hospital," an eyewitness said.

Police immediately arrived at the scene of explosion as residents were extinguishing the burning vehicle outside the Dahabshiil money transfer company, the biggest in Somalia.

Officials from the money transfer company said they were not the target of the latest attack but Dahabshiil has previously been targeted with bomb attacks.

No group has so far claimed responsibility for the bomb blast but the radical Islamist group of Al Shabaab is known to have carried out such attacks in the past.

Somali police cordoned off the area and began questioning witnesses about the explosion.

Although security has been improving in Mogadishu for the past two years, such attacks on key figures and on targets of Somali government installations as well as on African Union peacekeeping mission have lately been on the increase.