Daniel is described as a 'bit of a loner'
The mother of missing seven-year-old Daniel Entwistle has appealed to him: "Please come home, you are not in trouble."
Paula Entwistle sent the message to her son at a news conference and pleaded for anybody with information to contact police immediately.
Detective Superintendent Julian Gregory who is leading the search for Daniel said it was too early to know what has happened to him.
But he added: "If anyone is with Daniel we urge them to make contact as soon as possible."
Fears for Daniel grew after his bike was found on a riverside quay, 10 minutes from his home in Great Yarmouth, Norfolk.
Daniel was last seen at 1700 BST on Saturday and the search for him now involves police divers, helicopters and dog handlers, as well as 60 uniformed officers, lifeboat crews, the coastguard and local residents.
Daniel's mother said he had gone missing before, but that he was found two hours later - in the area where his bike was found.
Mrs Entwistle said Daniel could be 'mischievous'
Mrs Entwistle said: "He's outgoing, he's pleasant, he can be mischievous like a lot of children and he's a bit of a loner.
"But he says 'hi' to anybody. He has friends that live locally and we just thought he was there."
Mrs Entwistle, who has two other sons aged ten and two was comforted by Daniel's father, 41-year-old David.
The family originally come from Burnley in Lancashire, but moved to Norfolk three years ago to be nearer Mrs Entwistle's family.
After Daniel's bike was discovered it was covered with a white tent and examined by forensic officers.
It was close to the River Yare, which was searched by divers.
Det Supt Gregory, asked residents and visitors to the seaside resort to help them find Daniel.
He said: "I am sure we can all imagine the trauma the parents are going through and we want the public to help us."
Police are investigating a number of unconfirmed sightings of Daniel close to his home and have said the search will continue through the night.
Daniel is described as 3ft 2ins tall with a strong northern accent.
He was wearing a blue Adidas T-shirt with a motif on the chest, a blue track suit and grey trainers.