More than six thousand peacekeepers from Uganda and Burundi are in Mogadishu to protect the airport, seaport and other places. The United States has provided them with light weapons, training and other support.

Al-Shabab has also made new threats to target Burundi's capital, Bujumbura. But Uganda is the main provider of troops to the African Union Mission in Somalia. Uganda plans to send two thousand more troops. And President Yoweri Museveni recently joined other east African leaders in calling for a mission with twenty thousand troops.

He says Ugandan troops in Somalia have been involved only in defensive duties. Now, he is calling for an offensive against al-Shabab. But several Ugandan and other east-African politicians and commentators have urged Uganda to withdraw.

Uganda's main opposition leader this week asked why Uganda and Burundi are providing troops while other African leaders ignore the problem.

For three years, al-Shabab has led militants in battles -- mostly against the peacekeepers -- for control of Mogadishu. Only a few city blocks remain under government control.

Al-Shabab fighters during an exercise in Mogadishu early this year

Uganda sent the first troops in March of two thousand seven to help secure the capital. That was after Ethiopia's military ousted Islamists from power.

The bombings in Kampala have led to a number of arrests. An unexploded suicide bomb vest was found at a third location, a disco club.