At least 15 people have been killed in a massive fire that tore through a Rohingya refugee camp in Bangladesh, while at least 400 are still missing, the UN refugee agency UNHCR has said.
Tens of thousands have been left homeless in Cox's Bazar after fleeing.
Refugee aid groups estimate that between 40,500 and 50,000 people have been affected by the fire.
The settlement is part of a network of camps housing over a million refugees who have fled Myanmar since 2017.
"We still have 400 people unaccounted for, maybe somewhere in the rubble," UNHCR's Johannes Van der Klaauw, who joined a Geneva briefing virtually from Dhaka, Bangladesh.
UNHCR has reports of more than 550 people injured and about 45,000 displaced. At least 10,000 makeshift shelters have also been destroyed.
Refugees International quoted witnesses as saying many people, including children, were trapped by the barbed wire fencing around the camp in Cox's Bazar.
Many are seeking shelter in nearby camps, friends or families' shelters and learning centres, according to the World Food Programme, which also said some of its food centres were burnt to the ground.
"Even though the fire was brought under control, smoke is still billowing from many places," Mohammad Abdullah, deputy assistant director of the fire service from the camp, told BBC Bengali.
"Our teams are still working to remove the rubble. Locals have started cleaning their houses," he said, adding that an investigation committee was working to determine the number of casualties and the extent of damage.
'Reduced to ashes'
Witnesses told the BBC that the fire, which began on Monday, ripped through the settlement with startling speed.
Moyna Khatun said the fire suddenly swept in from the south.
"Initially I thought that the fire would be doused. That's why I didn't bring out my belongings from inside my house. When the fire turned devastating, I took shelter in a nearby graveyard. I'd never seen such a devastating fire in my life."
"Thousands of houses have been reduced to ashes," said another camp resident, Syed Alam.
"My daughter-in-law is pregnant," Shobe Meraj told the BBC. "I sold my gold to take her to hospital. All my money is burnt and my daughter-in-law is missing."
"These people, the Rohingya refugees, have already gone through extremely traumatising events over the last couple of years. They are obviously living under very, very challenging conditions. You can imagine that they are already dealing with lots of stress. And this event certainly going to further affect that," said Onno Van Manen, Bangladesh country director of charity Save the Children.
The refugee camp, said to be the world's largest, houses people who fled from neighbouring Myanmar, following a military crackdown against the Rohingya ethnic minority.
The Rohingya are Muslims in largely Buddhist Myanmar, where they have faced persecution for generations.
The latest exodus of Rohingya escaping to Bangladesh began in August 2017, after Myanmar's military brutally retaliated when a Rohingya insurgent group launched attacks on several police posts.