Libyan authorities blocked civilians from entering the flood-stricken eastern city of Derna on Friday so search teams could look through the mud and wrecked buildings for 10,100 people still missing after the known toll rose to 11,300 dead.

Derna was being evacuated and only search and rescue teams would be allowed to enter, Salam al-Fergany, director general of the Ambulance and Emergency Service in eastern Libya, announced late Thursday.