Gunmen have infiltrated a fortified regional headquarters in Somalia's central town of Baidoa that includes a UN facility and an airport. A police spokesman said regional government chief Sharif Hassan had escaped.
Suspected al-Shabab militants tried to fight their way into Baidoa's government compound on Thursday. Security officials spoke of at least one bomb explosion at the compound's entrance. Four soldiers and three gunmen have been killed.
A United Nations source quoted by the AFP news agency said aid agencies located inside the compound did not appear to have been the assailants' target.
"First a car bomb exploded at the southwest palace gate and then armed fighters went in," police spokesman Captain Ali Ahmed told Reuters.
Another police source quoted by AFP said al-Shabab assailants had entered by disguising themselves in Somali military uniforms.
On January 2, al-Shabab attacked a Baidoa army post, killing a number of soldiers, two days after the United States said it had killed Shabab intelligence chief Tahlil Abdishakur in a drone strike.
Al-Shabab's former leader Ahmed Abdi Godane was killed similarly in September.
Baidoa lies 220 kilometers (140 miles) northwest of Somalia's capital Mogadishu. Al-Shabab rule was ended in February 2012 by Ethiopian and Somali forces.
Hub of fourth new state
In November Baidoa became the hub of Somalia's fourth federal state, South West State. It is led by former parliamentary speaker Sharif Hassan Sheikh Aden, an ally of Somalia's internationally-backed government based in Mogadishu.
In recent years, a military campaign backed by African Union has reasserted Mogadishu government control over parts of Somalia but in some locations the situation has remained fragile.
ipj/sms (AFP, Reuters, dpa, AP)