NAIROBI (Reuters) - Kenya said its forces had killed 57 Islamist al Shabaab militants in a battle in southern Somalia on Wednesday, but the group denied any of its fighters had died in the clash.

Kenyan troops under the African Union command used artillery and helicopter gunships against the Islamists in Afmadow, a town about 100 km (60 miles) inland from the port of Kismayu, Kenyan military spokesman Col. Joseph Owuoth said in a statement.

“In the onslaught, 57 al Shabaab militants were killed and unknown number injured,” Owuoth said, adding that five gun-mounted pickup trucks known as “technicals” were destroyed.

Abdiasis Abu Musab, al Shabaab’s spokesman for military operations, said the Islamists had ambushed Kenyan soldiers, prompting them to call in air support, and that al Shabaab lost no fighters.

“The planes fired some bombs and KDF (Kenya Defence Forces) returned to their places. There is no casualty from our side and we do not have exact casualty numbers of KDF,” he said.

Somalia has been torn apart by civil war since 1991 and now a drought threatens to tip the Horn of Africa nation into famine. Last month parliamentarians elected a new president who vowed to stamp out al Qaeda-linked al Shabaab.

The insurgency wants to topple the government and impose its own strict interpretation of Islam on Somalia. It ruled most of south-central Somalia until 2011, when it was driven out of Mogadishu by African Union troops.

Despite the loss of territory, al Shabaab still carries out major gun and bomb attacks.

In January, its fighters attacked a Kenyan military base in the southern Somali town of Kulbiyow, near the Kenyan border. Kenya said nine soldiers died, while al Shabaab said it killed at least 66.

In January 2016, al Shabaab said it had killed more than 100 Kenyan soldiers in El Adde, a Somali camp near the border with Kenya. The military did not release casualty figures from that attack, but media reports supported al Shabaab’s death toll.