Officials in Somalia's capital, Mogadishu, say a blast has killed at least five government security officers.
The officials said a bomb exploded Wednesday, in the city's southern Afisiyooni neighborhood as the security officers passed by.
No one has yet claimed responsibility for the attack.
Somalia's transitional government has fought for more than three years with the insurgent groups al-Shabab and Hizbul Islam. The government now holds only small parts of Mogadishu, supported by an African Union peacekeeping force.
The insurgents gained ground and moved closer to the presidential compound during an attack late last month.
But Somali military officials said last week they had retaken several neighborhoods.
Last Thursday, witnesses said at least 17 people were killed in fighting between Islamist insurgents and pro-government forces.
Reports indicated government soldiers backed by African Union troops attacked insurgent-held positions. Officials say at least 55 people were wounded in the shelling and gunbattles.
The Horn of Africa nation has not had a stable central government since 1991. Fighting over the last several years has killed tens of thousands of people and displaced more than a million.
Some information for this report was provided by AP and AFP.