The mayor of the eastern Libyan city of Derna says about 8,000 people have so far been confirmed dead in massive floods there.

Following the floods triggered by heavy rain on Monday, teams from countries including Turkey, Egypt and Tunisia have reportedly rescued more than 500 people in eastern Libya. Qatar and some other countries are setting up makeshift hospitals in Derna.

The Derna mayor disclosed the death toll to NHK, but the full picture remains unknown as communications remain poor and roads have been cut off.

Buildings were swept away in wide areas of the city following the collapse of two dams.

The mayor said the number of victims could exceed 20,000, judging from the extent of the affected areas.

Local media say residents and rescuers are recovering bodies from under the debris. They also report concerns about outbreaks of infectious diseases, as several days have passed since the disaster and temperatures have been high.