By Abdiqani Hassan
BOSASSO, Somalia (Reuters) - Somali Islamist militants have killed at least 11 soldiers in an attack on a military base in the semi-autonomous Puntland region, a regional minister and the rebels said on Wednesday.
The attack underscores concerns that security in the relatively peaceful region will worsen after a large number of al Shabaab rebels were squeezed out of their southern and central strongholds by African troops and moved north.
Puntland's President Abdirahman Mohamud Farole last month told Reuters more than 400 al Qaeda-linked fighters were holed up in his territory, a development that could discourage plans for oil exploration in the region.
"Al Shabaab unexpectedly attacked our base and killed 11 of our forces and injured 7 others last night," Khalif Isse Mudan, Puntland's security minister, told reporters.
Seven militants were killed in the gunbattle, he said.
Until now, Puntland has largely escaped the worst of the upheaval in Somalia, which has been deprived of an effective central government for two decades.
Although militant numbers are still limited in Puntland, Western diplomats fear they may try and forge closer ties with al Qaeda militants in Yemen, separated from Somalia by a narrow stretch of water. Access to Puntland's ports would help the rebels ship in weapons.
Abdiasis Abu Musab, the spokesman for al Shabaab's military operations, said the militants had killed 17 Puntland troops.
Under pressure from African Union (AMISOM) peacekeeping troops and Somali government forces, al Shabaab has lost many of its urban strongholds in south-central Somalia since it launched a rebellion against the Western-backed government in 2007.
The rebels want to impose their strict interpretation of sharia Islamic law across the Horn of Africa state.
(Additional reporting by Feisal Omar; Editing by Richard Lough)