Rescuers are digging through mud and debris in the hunt for those missing after devastating mudslides in Colombia left more than 200 dead.
About 1,100 soldiers and police are involved in the relief effort.
Heavy rain flooded the city of Mocoa in the country’s south-west with mud and rocks burying whole neighbourhoods and forcing residents to flee their homes.
An army statement said there were at least 400 injured and 200 still missing in the capital of Putumayo province.
The exact death toll is hard to confirm with the rescue operation still under way.
Some local media estimate up to 300 people have been killed, while the Colombian Red Cross has a total hovering above 200.
The Red Cross said it was working to help family members contact each other.
Video footage from the city showed residents crying over a list of missing children, along with their ages, pinned to a family welfare centre.
“We have lost a baby, who has gone missing,” one resident told reporters. “A little baby, we can’t find him anywhere.”
President Juan Manuel Santos declared a state of emergency in the region and flew in to oversee the rescue effort.
“We will do everything possible to help,” he said. “It breaks my heart.”
A senior UN official in Colombia, Martin Santiago, blamed climate change, saying it had caused “tremendous results in terms of intensity, frequency and magnitude of these natural effects” in the region.
Others said deforestation has also played a role. “When the basins are deforested, they break down. It is as if we remove the protection for avoiding landslides,” said Adriana Soto, a Colombian conservationist and former environment minister.
The Colombian Air Force is bringing supplies to the area as the search operation continues.
With no running water in Mocoa, one resident told El Tiempo newspaper that they had been collecting rainwater. Power lines are also out across the area.
Photos posted to social media by the air force showed some patients being evacuated by air.
“Our heroes will remain in the tragedy zone until the emergency is over,” the army’s statement said.
Colombia’s director of the National Disaster Risk Management Unit told the AFP news agency that a third of the region’s expected monthly rain fell during one night.
Although rainfall is abundant in the area, this downpour was unusually heavy and caused rivers to burst their banks.
The overflow then picked up mud and debris, creating a cascade.
Video footage of the aftermath showed currents so strong that abandoned lorries were propelled through the flooded streets.
Local resident Mario Usale, 42, told Reuters he was searching for his father-in-law.
“My mother-in-law was also missing, but we found her alive 2km (1.25 miles) away. She has head injuries, but she was conscious,” he said.
Landslides have struck the region several times in recent months.
In November, nine people died in the town of El Tambo, about 140km (90 miles) from Mocoa, during a landslide that followed heavy rain.
Less than a month before that, another landslide killed several people near Medellin, almost 500km (300 miles) to the north.
And in neighbouring Peru, more than 90 people have died since the start of the year because of unusually heavy rainfall, which also caused landslides and flash floods.