Police, fire teams, helicopters and divers are searching the Wear for any sign of 8-year-old Ian Bell, who fell in the river on Friday.
It is believed that Ian fell in after going down to the river with two friends and playing on its banks.
Durham Police said it was still working on the basis that he is alive, and may have found shelter somewhere.
But Inspector Simon Orton said the local community were very worried.
"There are a lot of emotions obviously involved with the family, extended family and the friends."
"I can only guess at the emotions that those people are feeling but we're looking for an eight year old boy. We don't know where he is. That's got to create so much angst and desperation."
Teams of family and friends joined police to help with the search, with some volunteers walking more than 10 miles from as early as 6:30am this morning.
Jason Humble, who heard about Ian and volunteered to help, said: "I have an eight-year-old son and a three-year-old daughter and it's like losing part of your life basically, and so you just all club together and get on with it."
Local fisherman said that the currents on Friday night were incredibly strong, and that the river has been high after weeks of rain.
Friends said that Ian is an 'adventurous boy' who loved to play on his scooter, and was familiar with the river.