MOGADISHU: At least 24 people were killed in fighting that pitted Islamist insurgents against government forces and African Union peacekeepers in Somalia's capital Friday, witnesses and medical staff said. Residents were hiding in their homes as mortars slammed into the city.

The bloodshed came one day after fighting killed at least 40 people in central Somalia as the warring sides tried to gain ground in strategic towns.

Somalia has been ravaged by violence and anarchy since warlords overthrew dictator Mohamed Siad Barre in 1991, then turned on each other. The al-Shabab insurgent group, which has foreign fighters in its ranks, operates openly in the capital and seeks to overthrow the government and impose a strict form of Islam in Somalia.

The rebels launched a pre-dawn attack Friday on an African Union base, prompting a relentless firefight. Mortars slammed into a market as traders were setting up their goods for the day, killing six people. Ali Muse, the coordinator of Mogadishu's ambulance service, said another 18 bodies had been transported Friday.

"Hundreds of well-armed insurgents came to our district with minibuses and pick-up trucks and immediately they started firing towards the government troops and an African Union base," Mogadishu resident Abdi Haji Ahmed told The Associated Press by telephone. "We have been ducking under our concrete balcony for hours."

The government and African Union had no immediate comment.

But al-Shabab spokesman Sheik Ali Mohamud Rage said his forces retaliated against the African Union troops for rolling into rebel-controlled areas early Friday.

"They provoked us by coming into our areas, so we have a right to attack them in their bases," Rage said.

Government troops and African Union peacekeepers hold only a few blocks of Mogadishu, but they still control key government buildings as well as the port and airport.