It is "highly unlikely" that three people still missing in the rubble of the Didcot Power Station collapse are still alive, officials have said.
Chief fire officer Dave Etheridge said he had spoken to their families and explained that there had been no promising signs of life.
The structurally unstable building has continued to hamper search efforts, he said.
We are doing everything we can to locate their families and loved ones. Our thoughts sympathies and prayers are with them at this very, very difficult time.
The extent of this incident, the nature of the collapse and the location of the missing people, and where they were working means that it is highly unlikely that the three missing people are alive.
They had tried the workers' construction site radios with no response, he said, which was seen as "significant".
Vowing to do "everything possible" to find the missing people, he said sniffer dogs, listening devices and drones had been in use, and officers are now exploring the possibility of using remote control probes to search in areas which are too dangerous for emergency workers to access.
To date, one person has been confirmed as killed in the collapse, who has now been identified as a member of the demolition team.
Five people are in hospital after being seriously injured, but Ch Cons Scott Chiltern said they were in a stable condition.
Frustrated families of those missing since the power station collapse two weeks ago say they are heartbroken that rescue work has halted.
A biker group in the North East has paid tribute to 'Whitby' Mick Collings, who is thought to have died in the power station collapse.
One person has died and three others are still missing after a building collapsed at Didcot Power Station yesterday.