The African Union peacekeeping force in Somalia said the al-Qaeda-linked al-Shabab militants on Saturday shelled residential areas in the southern town of Baidoa.

“Al-Shabab militants fired mortar shells at densely populated civilian residential areas in Baidoa town this morning,” the African Union Mission in Somalia (AMISOM) said in a message posted on Twitter.

The militants also hit a hospital in the town, AMISOM said, adding that “civilian casualties are unknown but expected.”

Somalia has been the scene of fighting between al-Shabab and government forces since 2006.

In 2011, al-Shabab, striving to topple the government, was driven out of the capital Mogadishu and other major cities by government troops and AMISOM forces, which are largely made up of troops from Ethiopia, Uganda, Burundi, Djibouti and Kenya.

However, the militants still carry out sporadic attacks in the capital and elsewhere in the country.

International aid workers, journalists, civilian leaders and African Union peacekeepers have been among the victims of attacks by al-Shabab.

In late July, the militant group attacked a police station in Mogadishu with two car bomb blasts. Nine people, including four assailants, were killed.

The militants have also attacked targets in neighboring Kenya, looting government buildings there.

On July 10, more than 100 al-Shabab militants raided a police station in northeastern Kenya overnight, wounding one officer and making off with arms and ammunition.