More than 40 civilians have been killed in the Somali capital this week, the United Nations' humanitarian agency said Friday.

About 20 civilians were killed Thursday as Ethiopian and Somali soldiers battled insurgents in Mogadishu, the U.N. Office for the Coordination of Humanitarian Affairs said in its weekly report on Somalia.

The abduction of a Somali staff member of CARE International on Monday has raised the number of aid workers kidnapped in Somalia to eight, the U.N. agency said.

In a statement Friday, CARE International said it is suspending operations in the south central Somalia region of Galgudud following the abduction.

Somalia's shaky transitional government, formed in 2004 with the help of the United Nations, has been battling an insurgency by Islamic militants. Thousands of civilians have been killed and hundreds of thousands have been forced from their homes, particularly in Mogadishu.

After Islamic militants seized control of Mogadishu and most of southern Somalia in 2006, the government called in troops from neighboring Ethiopia to help oust them.

The insurgency that started soon after remains a potent and disruptive force, and a continuing threat to President Abdullahi Yusuf's government, which is backed by both the United States and European Union.

Somalia is also facing a worsening humanitarian crisis aggravated by high global food prices and drought. The United Nations has said 3.5 million Somalis will need humanitarian aid by the end of the year unless conditions improve.

The Horn of Africa nation of 7 million people has been in anarchy since warlords overthrew dictator Mohamed Siad Barre in 1991, and then turned on one another.