The death toll in Libya’s coastal city of Derna has soared to 11,300 as search efforts continue following a massive flood fed by the breaching of two dams in heavy rains, the Libyan Red Crescent said Thursday.

Marie el-Drese, the aid group’s secretary-general, told The Associated Press by phone that a further 10,100 people are reported missing in the Mediterranean city. Health authorities previously put the death toll in Derna at 5,500. The storm also killed about 170 people elsewhere in the country.

The flooding swept away entire families in Derna on Sunday night and exposed vulnerabilities in the oil-rich country that has been mired in conflict since a 2011 uprising that toppled long-ruling dictator Moammar Gadhafi.