Al-Shabaab fighters raided an African Union military base housing Ugandan troops in Somalia on Friday, triggering a fierce gun battle.

It was not immediately known if there were any casualties in the attack, which was claimed by the Al-Qaeda-linked jihadist group.

A car laden with explosives was driven into the base in Bulo Marer, 120 kilometres (75 miles) southwest of the capital Mogadishu, leading to a
gunfight, local residents and a Somali military commander told AFP.

Pro-government forces backed by the AU force known as ATMIS launched an offensive last August against Al-Shabaab, which has been waging an insurgency in the fragile Horn of Africa nation for more than 15 years.