As many as 500 villages were submerged by floodwater due to high torrents at Sukkur and Guddu Barrages on Friday.
The surrounding areas were put on high alert and rescue teams were also formed to help the stranded people.
The water level at the barrages was recorded at above 500,000 cusecs.
The floodwater has inundated villages in Katcha areas of Sukkur, Ghotki, Kashmore-Kandhkot, Shikarpur, Khairpur Mir’s Larkana and other districts.
Thousands of villagers have been displaced from their homes and have been shifted to safer places, officials said.
The chief engineer at Sukkur Barrage said all protective dykes had been fortified whereas heavy machinery and other materials had been deployed at all vulnerable points.
Also, over 200 villages of Kacha areas of Kandhkot district were inundated due to overflowing water from IndusRiver near Sukkur Barrage.
The National Disaster Management Authority (NDMA) on Friday said 169 people had died and 855 injured in recent floods and rains throughout the country.
According to the statistics released by the NDMA, 55 people died in Punjab, 24 in Khyber Pakhtunkhwa, 35 in Sindh, 18 in Balochistan, 12 in FATA and 25 in Azad Jammu and Kashmir.
A total of 1,419,569 persons have been affected by the floods in the country, including 634,322 in Punjab, 336 in Khyber Pakhtunkhwa, 720,641 in Sindh and 64,270 in Balochistan.
Crops spanning 826,871 acres of land were affected in various parts of the country and 25,573 houses were partially damaged, while another 20,046 were razed.
The NDMA said that 323 relief camps had been established throughout Pakistan in which 30,540 persons were residing.