Police and mountain rescue teams worked through the night to try to find five-year-old April Jones, who has been missing since Monday evening.
April was last seen getting into a light-coloured van at around 7pm on Monday. She had been playing with a friend on the estate where she lived, in Machynlleth, Powys.
Overnight a team of 40 officers, dog handlers and mountain rescue teams searched riverbanks near April's home, concentrating their efforts on the River Dyfi.
Yesterday Dyfed Powys Police arrested a 46-year-old man arrested in connection with April's disappearance. The man, who remains in police custody at Aberystwyth Police Station, has been named locally as Mark Bridger, but police have refused to identify him.
Police say they have recovered a Land Rover vehicle and it is being looked at by forensic officers.
Hundreds of local people helped to look for April yesterday, but last night officers scaled back the public search, saying the presence of vast crowds could "compromise" the search.
Specialist teams worked through the night using thermal imaging equipment.
In a press conference at just after 7.30am today, police said volunteers were no longer needed. "Can we please leave this now to the trained and skilled people that we have," said Supt Ian John.
He later added: "I don't want those officers to be distracted by the well-intentioned and enthusiastic support" of the public.
Supt Ian John also reminded the public of the "challenging conditions" in the area, which is rural. The poor weather overnight has resulted in the flooding of the River Dyfi, he added.
Supt Jones also explained that based on experience police expect to find April Jones close to where she went missing.
In a statement read out at a press conference last night, April's family said they were "shattered" by her disappearance.
They described her as a "beautiful little girl" and said: "Please, please if you have our little girl, let her come home to us."
Thousands of people have turned to social networking sites Twitter and Facebook to express their concern for April and her family.
Once Facebook Page, Find April Jones, has 127,704 'likes'.
Meanwhile April topped Twitter's trending list yesterday, with thousands of users discussing the unfolding situation.
UPDATE 1035: Police have confirmed the 46-year-old man arrested is indeed Mark Leonard Bridger, and they have released an image of him.
They have also released an image of a Land Rover Discovery recovered from a repair garage on Tuesday afternoon. The vehicle's registration is L503 MEP.
Police are appealing to the public to think back to whether they saw Mark Bridger or the vehicle between 5pm on Monday and 3.30pm on Tuesday. "If you did, please don't assume that someone else has already contacted us," police told a press conference at just after 10.30am.
Even the smallest piece of information could be "crucial", police stress.
Police also said Bridger was wearing a camouflage green jacket and black waterproof trousers with camouflage trousers underneath when he was arrested on Tuesday afternoon on the A487.
Anyone with information is urged to call 101. Alternatively, Dyfed Powys Police have issued a number for people who might have details about April: 0300 2000 333.
