At least eight people have died in an attack by suspected al-Shabab militants on a fortified government compound in the town of Baidoa, southern Somalia.

The attackers, who are said to have been wearing military uniforms, shot their way into the compound after setting off an explosion at the gates.

All five of the gunmen are believed to have been killed.

Al-Shabab continues to carry out attacks despite being weakened by drone strikes and an African Union operation.

The Islamist militants, who are allied to al-Qaeda, controlled Baidoa for three years until they were driven out by Ethiopian troops in 2012.

The compound in Baidoa houses UN offices, an airport and the headquarters of the regional administration for the newly created South West state.

The offices of the head of the administration, Sharif Hassan Sheikh Adan, were the intended target of the attack, according to a security official.

The attackers failed to reach his office, and the leader was unharmed, the official told AFP news agency.

Sharif Hassan is a close ally of Somalia's government, headquartered in Mogadishu, which is backed by more than 22,000 troops in an African Union contingent drawn from several countries.

Neighbouring Ethiopia, which sees the Islamists as a major threat to its security, also has troops in the country. Some of them are part of the AU force, while others operate independently.

Various armed groups have been battling for control of Somalia since the overthrow of President Siad Barre in 1991.