A Somali military official says heavily armed fighters from the Islamic extremist group al-Shabab have attacked a base for African Union peacekeepers in southwestern Somalia.

Ahmed Hassan said Friday that dozens of al-Shabab fighters started a complex attack on a military base, run by Kenyan troops who are part of the African Union force in the town of El-Ade, not far from the Kenyan border.

He said the attack started with a suicide car bomb, and then heavy gunfire was heard as militants stormed into the base.

Fighting is still going on inside the base, he said. He had no details about any casualties.

Al-Shabab reported on its online radio that its fighters had managed to penetrate the base and were fighting African Union troops.