The full extent of damage caused by massive floods in Libya remains unclear one week after their occurrence.
Rescue workers are facing piles of mud and other hazards.
Heavy rain brought by a low pressure system caused dams to collapse in eastern Libya on September 11. The city of Derna was hit by floods and buildings were swept away in vast areas.
Derna's mayor has said about 8,000 people are dead and the death toll could exceed 20,000.
Wide areas of the city are still covered with mud and search and rescue operations are not progressing as expected.
The United Nations says more than 40,000 people have been displaced, and relief supplies have yet to reach them. Officials say people in Derna are having difficulty obtaining safe drinking water.
UNICEF says nearly 300,000 children are exposed to such risks as diarrhea and cholera outbreaks.
UN officials are calling for urgent life-saving intervention.