The investigation into a farmhouse fire in Wales that is thought to have claimed the lives of a father and five young children could take many months, police have warned.
The children, aged between four and 11, were killed in the fire at the remote property at Llangammarch Wells, Powys last week.
The man who died has been named locally as David Cuthbertson who neighbours said "doted" on the children.
A neighbour raised the alarm and three children, aged 13, 12, and 10, managed to escape unharmed. They have since been released from hospital.
British Detective Chief Inspector Martin Slevin, who is leading the investigation, said: "The nature of this fire was so intense, the scene presents significant difficulties in respect of the recovery of any remains, and assessments of the scene, and this will take some considerable time.
"The investigation is ongoing and we continue to treat the cause of the fire as unexplained.
"Moving forward we will be assisted by a team of officers from South Wales Police and Gwent Police who have specialist knowledge and skills in recovering remains under these circumstances, and disaster victim identification."
"Dyfed-Powys Police specialists will continue to lead the investigation into the cause of this fire."
Addressing the community, Mr Slevin said: "We want to get this absolutely right for the family and will do all we can to understand what happened here.
"It is likely to take several weeks, if not months, to conclude our work. While we are at the scene up to 40 people will be at the site at a time, and you will notice an increase of police cars and officers around the town.
"I would like to thank the local community for their support and patience so far while we investigate this tragedy, and hope that this continues as we move forward."
Chief Superintendent Tony Brown, of South Wales Police, added: "My role in this investigation is to preserve the integrity of the evidence at the scene, all the while making sure the process is sympathetic and caring, and we maintain respect for both the deceased and bereaved.
"In the coming days and weeks experts are facing the task of carefully taking down the outer walls of the house - 260 tonnes of bricks and mortar - by hand.
"Once complete, we will section-off the inside of the house and begin the delicate search for those inside.
"There will be specialist scientists at the scene to look at what we find."