Authorities of Haryana's Panchkula and Ambala districts on Saturday issued a flood alert following a rise in the water level of Ghaggar river.
At least three children, who were swimming in the river, were washed away and were stranded on an island in the river. Rescue teams are trying to save them.
Officials in Panchkula district said the water level in Ghaggar river had risen in the last 24 hours, following heavy rains in catchment areas of neighbouring Himachal Pradesh.
"We have sent teams to rescue the children who were washed away in the Ghaggar river," Panchkula's deputy commissioner Ashima Garg said.
Residents of Panchkula said that over-flowing water from the river was on the verge of entering their homes.
Floods have affected over one dozen districts of Punjab and Haryana, leaving 40 people dead and submerging over 2,000 villages and around 300,000 acres of agricultural land.