At least 40 houses swept into the sea after River Swat overflowed into Madyan Friday morning, confirmed the Swat deputy commissioner.
Six people have reportedly been killed, while 11 remain missing. The area residents have been conducting rescue operations.
The flood occurred following heavy rains in the area on Thursday.
A bridge has also been destroyed by the heavy current.
In Mansehra, seven people of the same family died in the flood. Three bodies have been retrieved, while the search is under way for other bodies, said the authorities.