A suicide bomber rammed his vehicle into a government convoy carrying a Qatari delegation in Mogadishu Sunday, killing at least 14 people, Somali officials and witnesses said, dpa reported.
The dead included 13 civilians, a soldier and the attacker. At least 18 people were injured.
The Qatari delegation escaped unharmed, government spokesman Abdirahman Osman Yarisow told reporters.
"It is unclear whether the target of the attack was the Qatari officials or not," he said.
The al-Qaeda-linked group al-Shabaab claimed responsibility for the attack.
The car exploded at a roundabout at the busy KM4 junction where several bus stops are located, Mogadishu governor Abdi Mohamud Warsame told dpa.
Mahdi Ali, who runs a shop near the junction, said his cousin Abdinasir was killed in the bombing.
"I saw the bodies of more than 14 people with my own eyes. All were innocents and I know six of them personally," Ali told dpa.
Another witness, Kiin Omar Makaraan, said, "I saw bodies of seven people. Their bodies cut into pieces."
Doctors at the Madina and Banadir hospitals said altogether 18 people were admitted for treatment.
The attack came after a three-day road lockdown was eased. Security along the city's arterial roads was tightened Wednesday after al-Shabaab threatened more attacks.
The group has been waging an insurgency against the government since 2007, but has ceded ground to African Union troops who have secured key regions in the Horn of Africa nation.
Al-Shabaab was forced to retreat from Mogadishu in August 2011, but have since managed to stage bombings against civilian and government targets in the city.
President Hassan Sheikh Mohamoud condemned the attack and asked security forces to double their efforts against the extremists.
The attack came two days before an international conference in London to support Somalia in its process to restore security.
The country was left without a federal government for 20 years, after the overthrow of military ruler Mohamed Siyad Barre in 1991.