An African Union official says hundreds of Ugandan troops have arrived in Somalia's capital, Mogadishu, to strengthen the AU force that supports the Somali government.
The AU deputy special representative for Somalia, Wafula Wamunyinyi, says the new troops began arriving on Friday.
He told reporters Monday that Burundi also plans to send a battalion, and that the AU force aims to drive Islamist militants out of the capital.
Ugandan troops make up the bulk of the AU force, which often battles the militant groups trying to topple the government.
A medical official says renewed fighting in Mogadishu Monday killed at least 11 people and injured about 50 others. The figures were provided by Ali Muse, head of Mogadishu's ambulance service.
Earlier Monday, a spokesman for militant group al-Shabab said the group has started a new offensive.
Uganda pledged to send more troops to Somalia after al-Shabab carried out twin bombings in the Ugandan capital of Kampala last month, killing 76 people.
When completed, the ongoing deployment will increase the number of AU soldiers in Mogadishu from 6,000 to 8,000.
The AU force has enabled the Somali government to keep control of key sites in Mogadishu -- the airport, seaport, and presidential palace.But the insurgents control most of the capital and much of southern and central Somalia. Al-Shabab and fellow Islamist group Hizbul Islam have moved to implement a harsh form of sharia, or Islamic law, in the areas under their rule.
Some information for this report was provided by Reuters.