Only Uganda and Burundi have sent peacekeepers to Somalia
A Ugandan soldier serving with the African Union (AU) peace force in Somalia has been killed by a roadside bomb in the capital, Mogadishu.
The attack took place near the international airport where most of the peacekeepers in Somalia are based.
So far only about 2,200 of a planned 8,000-strong AU peacekeeping force have been sent to Somalia.
Meanwhile, the UN children's agency has warned about the number of children being killed in the conflict.
Unicef says more than 150 children have been killed or injured in shelling, bombings and crossfire in the past year as Ethiopian-backed Somali government troops have battled Islamist insurgents.
The BBC's Mohammed Olad Hassan in Mogadishu says only last week five children were killed as they were fleeing from school and two more died while playing football on a public pitch.
Unicef's Hannan Sulieman said the intensified conflict was affecting children "far more" than in the past.
The conflict is believed to have created more than one million refugees
Children were being recruited to fight, and many more were malnourished, she told the BBC's Network Africa programme.
"The situation in Somalia has been noted to be the worst it has ever been, particularly in Mogadishu and the outlying areas," she said.
AU troops have not been able to quell the violence, which has triggered what aid workers say may be the worst humanitarian crisis in Africa.
It is estimated that the conflict has created more than one million refugees.
In December 2006, Ethiopian troops helped the transitional government oust Islamist forces who had been charge of southern Somalia for much of that year.
Somalia has been devastated by conflict since 1991, when former President Mohamed Siad Barre was ousted.