A suicide bomber from Somalia's Shebab insurgents has killed at least 12 people and wounded 27 others by ramming a vehicle packed with explosives into a convoy of African Union troops, officials say.
The attack, the latest in a string of killings, comes exactly one week after a US airstrike killed the chief of the Al-Qaeda-linked Shebab rebels, Ahmed Abdi Godane, prompting threats of retaliation from the extremists.
"The car packed with explosives hit one of the armoured trucks... 12 civilians in a minibus were killed, and 27 others were wounded," local governor Adukadir Mohamed Sidi said on Monday.
The bomb, which Shebab spokesman Abdulaziz Abu Musab called a "blessed attack" is the first major assault since the Shebab commander was killed in the US strike.
The Shebab boasted of killing foreigners including four Americans and a South African in the attack, but witnesses and the government said there was no evidence to back up the claim.
Two soldiers from the African Union Mission in Somalia (AMISOM) were wounded in the attack, Sidi added.
The attack took place near the town of Afgoye, some 30 kilometres northwest of the capital Mogadishu.
Somalia's government on Saturday warned of a wave of retaliatory attacks by the Shebab following the killing of their commander.
On Friday the Pentagon confirmed that Godane, the leader of Al-Qaeda's main affiliate in Africa, died in an attack in which US drones and manned aircraft rained Hellfire missiles and laser-guided bombs on a gathering of Shebab commanders.
The attack on the AU convoy comes after soldiers in the internationally funded force were accused of gang-raping women and girls as young as 12, and trading food aid for sex, in a damning report by Human Rights Watch on Monday.
