Police in Wales are to continue with their searches for missing girl April Jones tonight, regardless of weather conditions.
The five-year-old went missing on Monday evening while out playing in Machynlleth.
Dyfed Powys Police Superintendent Ian John said he is "very heartened" that the force had received more than 2,500 phone calls with information.
Police officers from across England and Wales are helping to field the calls.
Mr John, who was wearing a pink ribbon in support of a campaign by the girl's family, said investigators remain "determined" to find April.
Volunteers with "good local knowledge" have been asked to help search 32 villages around Machynlleth in Powys.
Police have meanwhile been given until 5pm tomorrow to question the man arrested on suspicion of her abduction.
Mark Bridger, 46, is to be interviewed again today to try to "piece together" his movements around the time the girl disappeared.
Police revealed last night that April has cerebral palsy and needs medication.
More than 220 police officers and mountain rescue personnel have joined the operation.
There are over 100 mountain rescue experts, 100 police-trained search officers, 20 dog-handlers, two vessels to search the river, a team of kayakers, and the Dyfed Powys Police marine unit.
Three UK experts have also been drafted in to help with the search.
Mr John said: "There are a large number of sites we are looking at.
"They are very varied in nature and the terrain that we are working in and the geography that we are working in is very challenging.
"It's been described to me as a hostile environment. By that, I mean the ground is quite treacherous and we have had a lot of rain."
Machynlleth mayor Gareth Jones said there was a sombre mood around the village.
He said: "Everybody is on hold and there is only one thing on everybody's minds - to get April home safe and sound. It's a mood of worry, anticipation and uncertainty."