Authorities in Somalia say 13 people were killed during fighting between insurgents and government troops in the capital, Mogadishu.
The Associated Press says the majority were victims of mortar attacks near the Bakara market and the presidential palace.
An additional 21 people were wounded in the attacks.
There have been several weeks of intense clashes between forces from the United Nations-backed government and al-Shabab insurgents.
The al-Shabab movement is trying to overthrow the Somali government and set up a strict Islamic state.
Al-Shabab controls large parts of the capital, Mogadishu, and much of Somalia's central and southern regions.
The weak Somali government is still holding on with the help of African Union peacekeepers from Uganda and Burundi.
Somalia has not had a functioning government in more than 20 years.
Some information for this report was provided by AP, AFP and Reuters.