Many families in Mocoa stayed up through the night to search through the debris, despite the lack of electricity in the city.
"I need to know where they are, if they are injured or where to find them," sobbed Maria Lilia Tisoy, 37, looking through the rubble for her two daughters, one pregnant, and a 4-year-old granddaughter. "If they are dead, please God deliver them to me."
President Juan Manuel Santos made a second visit to the area yesterday. He said water and energy services would be restored as soon as possible.
Santos blamed climate change for the disaster, saying Mocoa had received one-third of its usual monthly rain in just one night, causing the rivers to burst their banks.
There was disagreement over the death toll for most of yesterday but, late in the day, the Government's total was increased to match the 254-person figure released by the army. Just over 200 were injured.
Disaster officials said more than 500 people were staying in emergency housing and social services had helped 10 lost children find their parents.
The disaster came after deadly flooding in Peru killed more than 100 people and destroyed infrastructure.
Families of the dead will receive about US$6400 ($9150) in aid and the Government will cover hospital and funeral costs.
Even in a country where heavy rains, a mountainous landscape and informal construction combine to make landslides a common occurrence, the scale of the Mocoa disaster was daunting compared to recent tragedies, including a 2015 landslide that killed nearly 100 people.
Colombia's deadliest landslide, the 1985 Armero disaster, killed more than 20,000 people.
Santos urged Colombians to take precautions against flooding and continued rains.
The President also thanked China and the Inter-American Development Bank for donating US$1 million and US$200,000 respectively toward relief efforts.
- Reuters