Members of the public concerned about the disappearance of a Sheffield pensioner have formed their own search parties to try to find him.
Residents have used the South Yorkshire Police Facebook page to inform officers of locations they have searched and to suggest other places to check.
George Rodgers, aged 84, has not been seen or heard from since leaving his home in Ecclesfield at 4pm on Tuesday to visit a local park.
The OAP, who is married and has a wife, has Alzheimer's.
He did not take any money with him when he left home.
Chief Inspector Richard Lambert, of South Yorkshire Police, said: “We are now very worried about George’s welfare as he has potentially been outside for two nights.
"In this warm weather, and with George’s old age, this can cause all sorts of health problems and both we and his family are anxious to find him.
“We have a team of dedicated detectives who are sifting through all of the information we have about George, as well as a number of reported sightings that have been passed to us by the public.
“I want to express my gratitude to everyone that has so far come forward to report potential sightings of George, as well as those of you who are offering to help officers search specific areas for him.
“We are following up all reported sightings of George to try and piece together his movements since he went missing, so we can have a better idea of where to concentrate our searches.
“At present, we are focussing in and around the Ecclesfield area of Sheffield as this is where he was last seen and where we know he liked to walk in the park. However, if you believe you have seen George wandering further afield, or have come across someone matching George’s description, please let us know.
“I’m grateful for the public’s continued vigilance and for your commitment to finding this vulnerable elderly man and bringing him home safely.
“I’d ask that you check your back gardens, outbuildings or sheds and garages if you have them, as it’s possible George may have tried to seek shelter from the sun.”
Mr Rodgers is around 5ft 6ins tall, of a medium build, with thin, white hair.
He was last seen wearing blue jeans and a blue long-sleeved polo shirt.
When he left home, he was carrying an A4 framed picture of a former Sheffield United player.