The UN refugee agency has said that more than 100,000 Somalis have fled near-daily atrocities including rape, the shelling of civilian areas and general fighting since May.
A series of civil wars and the Ethiopian invasion and occupation from 2006 to 2008 has led to the deaths of thousands of civilians and sent hundreds of thousands more fleeing for their lives in recent years.
About 200 people died during a surge of violence in Somalia since last month as rebels launched a major offensive against the government and African Union peace-keeping troops. The rebels accused the government of perpetuating foreign occupation by allowing the AU force to remain.
'It's a critical humanitarian situation, with regular atrocities being committed,' UNHCR spokesman William Spindler told reporters in Geneva. 'We are particularly concerned about how the fighting is affecting a population that has already endured several decades of war.'
Somalia has not had a functioning national government since 1991.