Sindh is now the worst-affected in Pakistan in terms of surface area. Out of its 23 districts, 19 have been ravaged by floods, the UN Office for the Coordination of Humanitarian Affairs (OCHA) said Friday.
The Pakistani authorities have ordered an evacuation from Thatta after the swollen Indus river burst its banks.
The month-long devastating floods, the worst in Pakistan's history, have killed at least 1,600 people, affected over 20 million others and destroyed 900,000 homes.