A suicide bomber has blown himself up in a military camp in the Somali town of Galkayo, killing four officers, officials say, an attack claimed by the al Qaeda-linked al Shabaab group.
The dead included a military commander and two colonels, the town's Mayor, Hirsi Yusuf Barre, told Reuters on Saturday.
The camp houses a force made up of soldiers from the country's semi-autonomous regions of Puntland and Galmudug who have been integrated into the federal army under efforts to unite the fractured country.
"The death toll may rise," police officer Abdirahman Haji said.
Al Shabaab's military operation spokesman, Abdiasis Abu Musab, said it killed five people in the attack.
Al Shabaab is fighting to topple Somalia's central government and establish its own rule based on its interpretation of Islamic law.
Since withdrawing from Mogadishu in 2011, the group has lost control of most of Somalia's cities and towns. But it still retains a strong presence in regions outside the capital.