A deluge of water from three overflowing rivers swept through south-west Colombia while people slept, destroying homes and killing at least 154 residents, authorities have said.
The incident triggered by intense rains happened at around midnight in Mocoa, a city of about 40,000 tucked between mountains near Colombia’s southern border with Ecuador.
Muddy water and debris quickly surged through the city’s streets, toppling poorly constructed homes, ripping trees from their roots, lifting cars and trucks and carrying them downstream.
Many of the residents did not have enough time to climb on to their roofs or seek refuge on higher ground.
According to the Red Cross, 400 people are injured and 220 believed missing.
President Juan Manuel Santos declared a state of emergency and warned the death toll could rise. More than 1,100 soldiers and police officers have been called to help the rescue effort.
“We don’t know how many there are going to be,” he said of the fatalities when he arrived at the disaster zone.
“We’re still looking.”
He added: “Our prayers are with the victims. We will do everything possible to help them. It breaks my heart.”
Witnesses described feeling buildings vibrate and though an alarm reportedly went off to alert residents, it could not be heard throughout the city.
Videos residents posted online showed vast areas filled with wooden planks and debris.
Some could be heard calling out the names of people missing.
“In the middle of the night and this morning people lost loved ones,” interior minister Juan Fernando Cristo said.
“They lost families, boys, girls, young people, the elderly.”
The Red Cross planned to set up a special unit in Mocoa to help relatives search for their loved ones.
“At this moment, it’s chaos,” said Oscar Forero, a spokesman for the Colombian Red Cross. “There are many people missing.
“There are many people looking for their relatives,”
Carlos Ivan Marquez, of the National Disaster Risk Management Unit , said in a statement: “We have sent a team of 150 people to make our response effective and machinery began work immediately.
“We will be with the governor and the mayor giving all necessary attention.”
Herman Granados, an anaesthetistologist at the local hospital, said he arrived early on Saturdayyesterday morning and worked throughout the night on victims.
Granados said the hospital does not have a blood bank large enough to deal with the magnitude of the crisis and was quickly running out of supplies.
He said some of the hospital workers came to help even though their own relatives remained missing.
“Under the mud,” he said.
“I am sure there are many more.”
The BBC reported rescue services as saying their efforts had been hampered by continuing bad weather and damaged infrastructure. At least two bridges have been swept away.
“There are mobility issues on almost 80 per cent of the roads, and from where the road ends, it is three hours to where the landslide took place,” one police officer was reported to say.
The mayor of Mocoa, Jose Antonio Castro, reportedly told Caracol radio that the town was “totally isolated”, and was without electricity and water.
Castro said his own house had also been destroyed.
“The mud is up to the roof,” he said.
“The figures have been going up and in the crisis room they kept reporting more dead, we hope to God that it won’t go up too much because it is very sad. A big portion of the many houses were just taken by the avalanche [of water and mud], but above all the people were warned with enough time and they were able to get out. But houses in 17 neighbourhoods have basically been erased.”
The mudslides were said to have been caused by the rise of the Mocoa river and three tributaries.In all, 17 districts were reported to have been affected.
Landslides and heavy rain are said to be common in the Putumayo province, which borders Ecuador and Peru, however March was Colombia’s rainiest month since 2011.
Photos posted on Twitter by the Colombian air force showed streets filled with mud and debris as residents searched for survivors in waist-high water.