April Jones's family have refused to give up hope of finding her alive despite police announcing that her disappearance has now become a murder inquiry.
The five-year-old's mother, Coral Jones, asked her niece to post a message online saying: "I am not giving up hope and have not been told my daughter is dead yet - please stay hopeful."
The reaction was echoed by April's friends and by her teachers, who said they were still "praying that April is alive".
The news that Mark Bridger, the man being held on suspicion of abducting April, had now been re-arrested on suspicion of murder was greeted by a stunned silence at a leisure centre in Machynlleth, Powys, where volunteers had turned out yet again to search for April, only to be told by police they were no longer needed.
Supt Ian John said that because of the "significant development" it was "no longer appropriate for us to expect untrained members of the public to continue the search".
He said: "Now we only require professional searchers to be involved in the ongoing search, which continues in and around Machynlleth."
He added: "Despite the developments in our investigation our focus remains on finding April and the search continues."
Romy Shovelton, 62, from the nearby village of Carno, was among those waiting in a hall opposite the leisure centre.
She said: "At about 11am we were told there was going to be an announcement. Everyone went completely quiet, you could have heard a pin drop.
"Absolutely everybody in the community is feeling like one heart beating all together. It is devastating."
Supt John said of the volunteers: "They have been a vital part of our team throughout this search operation. Quite frankly, their commitment has been an inspiration to us all."
The most intense activity in the search appeared to be focussed on a steep river bank near the hamlet of Ceinws, where Mr Bridger has lived for the past month, following a report that a man was seen carrying a black bag there at 1pm on Tuesday.
Carwen Sheen, 36, was chatting to a friend on the opposite river bank when they saw the figure scrambling down a gulley leading to the water's edge.
A team of 12 officers moved in to clear shrubs and vegetation using long-handled shears, pick-axes, spades and forks, then begin the painstaking work of sifting through the soil and shale underneath.
All of the vegetation and large stones were cleared and put into a police Transit van.
A woman who lives close to the scene said: "They have cleared a very specific piece of hillside. It isn't a routine search of the area like the others that have been going on."
Specialist sonar equipment was also being used to scan the bottom of the River Dyfi and its tributaries for any objects below the water.
Supt John said: "We are focusing our search on the areas where we believe that we have got the best chance of locating April."
April's head teacher, Gwenfair Gwyn, said no-one was prepared to believe that April is dead.
She said: "The whole school, pupils, staff and parents are desperately worried by today's news, but we are still clinging to hope that April will be returned to us.
"As more time goes on we are becoming increasingly concerned for her safety but we refuse to give up hope and are praying that April is alive.
"This week has been the hardest in the school's history, an emotional roller coaster, but everyone has rallied around and provided tremendous support for the school and its community, and we are very grateful for that."
The fence around the school, a short walk from April's home, was covered with pink ribbon as a show of support to her family.
Chris Coleman, the manager of the Welsh football team, was among the growing list of people who have sent messages of support to April's family.
He said: "I can't imagine what her parents are going through, it's an unthinkable situation.
"All my players and staff send our love, prayers and thoughts to her family."