Officials in Somalia say Al-Shabab militants early Friday stormed a military base manned by African Union forces from Uganda, multiple sources said.

The dawn attack took place in Bulo Marer, an agricultural town in Lower Shabelle region, about 110 kilometers south of Mogadishu.

The militants detonated four to six explosions, including improvised bombs in vehicles driven by suicide bombers, three sources, including a local official and a security commander requesting anonymity because they are not authorized to speak to the media, told VOA Somali.

According to the sources, the militants penetrated perimeters of the base after the explosions, which were followed by a fierce firefight. The militants were also seen inside the town. The base is just outside town.

The situation of a second base manned by Somali forces not far from the AU base that al-Shabab claims to have attacked is unclear.

The group sent a message via Telegram early Friday claiming they were "overrunning" the base. The Africa Union military command and the Somali government have not yet commented on the attack.

The group sent a message via Telegram early Friday claiming they were "overrunning" the base. The AU mission confirmed the attack, and said they are assessing the security situation.

An al-Shabab attack on the same base in April 2018 failed after the Ugandan forces held their positions. Somali officials said dozens of militants were killed at the time.

This latest attack comes as the Somali government prepares the second phase of military operations against al-Shabab. The first phase, launched in August, drove al-Shabab from vast territories in central Somalia.

The Somali government said it will raise enough forces to takeover security responsibilities from the AU peacekeepers by Dec 2024.