MOGADISHU (Reuters) - Islamist al Shabaab militants killed at least 12 Somali soldiers and briefly captured a military base southwest of the capital on Wednesday, officials said, underscoring the insurgents’ ability to launch attacks despite a government offensive.

A suicide bomber detonated at the El Salini base before gunmen stormed in and briefly occupied it, police said. The military recaptured the base after reinforcements arrived.

“They took the base and took weapons and ammunitions, this includes anti-aircraft guns fixed on pickups,” said Nur Ahmed, a police officer from Afgoye in Lower Shabelle region.

Military officer Ismail Ali said 12 soldiers were killed and the commander of the base was injured.

Al Shabaab claimed responsibility.

“We took the base. We took two pickups with anti-aircraft guns hooked on. We destroyed four other military vehicles,” Abdiasis Abu Musab, al Shabaab’s military operation spokesman, told Reuters.

He said the attackers had killed 15 soldiers.

Al Shabaab has been fighting the U.N.-backed Somali government for more than a decade in a bid to impose their strict version of Islamic law.

The Horn of Africa nation has been in the midst of civil war since 1991, after warlords overthrew a dictator but then turned on each other.