A convoy of the African Union’s AMISOM force was targeted by a car bomb just outside the Somali capital on Monday, witnesses and a Somali army source said, though it was not immediately clear if there were any casualties.

A convoy of the African Union's AMISOM force was targeted by a car bomb just outside the Somali capital on Monday, witnesses and a Somali army source said, though it was not immediately clear if there were any casualties.

The attack took place near a checkpoint on the road linking Mogadishu and the town of Afgoye, "where a suicide bomber rammed his car into an AMISOM convoy," witness Abdulahi Mohamed said.

"There was a heavy explosion at the Alamada area... , we don't know about the casualties but I saw military ambulances rushing to the scene," he said.

A Somali military official, Omar Adan, confirmed the attack, but declined to give the number of casualties. He however blamed militants from the Shebab, which have multiplied attacks in the Somali capital since the start of the year.

"Al-Qaeda linked militants, who have lost ground, are attempting desperate attacks," Adan said.

On Saturday, a car bomb went off in central Mogadishu near a hotel popular with government officials and businessmen, injuring at least one person, though no claims were made for the attack.