Four Somali soldiers and a civilian have been killed after Islamist insurgents attacked a check-point just outside the capital, Mogadishu.
Islamists stage hit-and-run attacks since being ousted from the capital
The Islamists briefly took control of the site, burned military vehicles and seized weapons and money, a police officer said.
The Siinka Dheer check-point is on the road to Afgooye, where thousands of Mogadishu residents have fled.
The Islamists have also staged several attacks outside the capital.
In Baidoa, the seat of the transitional parliament, the insurgents launched a grenade attack, killing a general from the Somali forces and injuring two civilians.
And in the southern town of Goobale, insurgents clashed with Ethiopian troops.
The BBC's Mohammed Olad Hassan in Mogadishu says four civilians were killed and scores injured.
Several hundred people were displaced by the fighting.
"There was a fierce battle and the Ethiopians shelled the village killing four civilians. We do not know the casualty figures among the combatants, we ran for our lives," said Sayid Ahmed, who fled the town to Wanlaweyn, 90km south of Mogadishu.
"Our aim is to cripple both the military and the economic sources of the enemy," Islamist spokesman Abdi-rahin Isse Adow told the BBC.
Our correspondent also reports that Islamist forces have marched unopposed into Hudur town, 180km north of Baidoa.
"The fighters have taken two positions at different directions of the town, they are here and there is no violence. We do not know whether their aim is to take the town or not," a resident told BBC on condition of anonymity for fear of reprisal.
Earlier this week, the US bombed an Islamist-held town in southern Somalia, saying that an al-Qaeda operative was sheltering there.
The Islamists were ousted from the capital, Mogadishu in December 2006 by government forces, backed up by Ethiopia, with some intelligence from the US.
The US accused the Somali Islamists of harbouring those responsible for the 1998 attacks on its embassies in Kenya and Tanzania.
The Islamists denied this, as well as reports they had links to al-Qaeda.
Somalia has not had an effective national government since 1991.
Last month, a senior UN official told the BBC that Somalia was the worst place in the world for children.