Al Shabaab fighters attacked a remote Somali army base and entered a nearby town close to the border with Kenya on Friday, saying they had killed dozens of Kenyan soldiers in an African Union force supporting the government during the assault.

Somali and Kenyan military officials said the fighters had seized the Somali army base near the town of Ceel Cadde, about 550 km (340 miles) west of Mogadishu in a region near Kenya’s border. A spokesman for the African Union peacekeeping force AMISOM said the battle for the base was still under way.

Al Shabaab said it had killed more than 60 Kenyan soldiers from AMISOM. Kenya’s Defense Ministry said both sides had suffered casualties but said numbers were not confirmed. An AMISOM spokesman said the al Shabaab toll was exaggerated but did not give a figure. There was no independent figure.