The number of casualties was unclear after al-Shabaab militants attacked a military base in southern Somalia, an army officer announced on Sunday.

He did not disclose the exact number of casualties, but the militant group said that 26 soldiers were killed in the incident in the southern port city of Kismayu.

Sources could not confirm the claim.

“We understand al-Shabaab attacked the base and fierce fighting and a blast occurred, but still we have no details,” Mohamed Isa, a military officer, told Reuters from Kismayu.

The attack was on a base in the village of Bala Gudud, near Kismayu.

State radio also reported the base had been attacked but said casualties were not yet known. The base is jointly operated by the Somali national army and forces from the semi-autonomous Jubbaland region of southern Somalia, it reported.

Residents in Bala Gudud said a blast was heard and an exchange of gunfire broke out shortly in the morning.

Abdiasis Abu Musab, al-Shabaab’s military spokesman, told Reuters: “This morning, we stormed the Jubaland base near Bula Gudud. We killed 26 soldiers and burnt two cars.”

The militants left the base after taking weapons, ammunition and several vehicles, he added.

On Friday, a US statement announced that a US military strike killed a Shabaab fighter and wounded another near Barawe town in southern Somalia’s Lower Shabelle region.

The strike took place on Thursday, the US Africa Command said.

At least one missile struck a location outside Barawe that the extremists often use to launch attacks on the government-held town, a Somali intelligence official said. He declined to give further details.

The US military has carried out several airstrikes against fighters with the al-Qaida-linked al-Shabaab in the Horn of Africa nation since President Donald Trump approved expanded military operations against the group.

That includes more aggressive airstrikes and considering parts of southern Somalia areas of active hostilities.