MOGADISHU (Reuters) - 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.

Somali and Kenyan military officials said fighters 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.

Al Shabaab said it killed more than 60 Kenyan soldiers from the African force AMISOM, which said there was a battle for the base without giving details. Kenya’s Defence Ministry said both sides suffered casualties but said numbers were not confirmed.

“Our gallant soldiers reacted swiftly to protect their camp,” Kenyan President Uhuru Kenyatta said. “Regrettably, some of our patriots in uniform paid the ultimate price.”

But he said “we will not be cowed” by the attack, which al Shabaab said was to drive Kenyans and others out of Somalia.

A shopkeeper in the Ceel Cadde town said soldiers from AMISOM appeared to have left the town and fighters were on the streets. “We see al Shabaab in every corner of town,” shopkeeper Abdullahi Iidle told Reuters. “Some residents have fled.”

Al Shabaab has been driven out of major strongholds in Somalia by AMISOM and Somali army offensives launched last year. But the group still controls some rural areas and often launches guerrilla-style assaults and bomb attacks.

The group, which is aligned with al Qaeda, said it took over the base after a suicide bomber rammed its gates, and also controlled the town, capturing nearly 30 trucks and armored vehicles.

“This attack sends a clear message to the Kenyan government that their military’s invasion of our Muslim lands and the massacre of innocent Muslims perpetrated by the Kenyan crusaders will not be without severe consequences,” al Shabaab said.

The group, which said it would “expel” the invaders, said in a statement that more than 63 Kenyans soldiers were killed.

Al Shabaab, which said the base was overrun, has inflated casualty figures in the past, while the Somali government and other official estimates often play down numbers.

The Kenya Defence Forces (KDF) said al Shabaab fighters overran the Somali army base and AMISOM had counter-attacked. A senior Somali military official also confirmed the militants had taken over the base.

“AMISOM has gone out of the town and base for strategic reasons,” Somali Colonel Farah Surow, who is based about 100 km (60 miles) from the Ceel Cadde base, told Reuters.

African Union troops, now numbering about 22,000 from several African nations, have spent nearly a decade battling al Shabaab insurgents in Somalia, a country mired in conflict since civil war broke out in 1991.

Al Shabaab has in the past year staged multiple attacks against African Union bases in Somalia, part of a guerrilla warfare strategy to drive out foreign troops and impose its harsh version of Islamic law across the Horn of Africa nation.