Weeks of heavy rain have created a risk of landslips in several provinces
At least 26 people have died in a mudslide that buried some 20 homes in a poor district of the city of Medellin, Colombian authorities have said.
More than 100 people continued the search for survivors on Monday.
Rescue efforts at the site, which is perched on the side of a mountain, have been hampered by the tough terrain.
Heavy seasonal rains have been blamed for the mudslide. Across the country, more than 100,000 people have been driven from their homes by flooding.
The floods have also swept away bridges, blocked roads and damaged crops.
Among those killed in Saturday's mudslide in Medellin were a pregnant woman and a boy who would have turned 15 on Sunday, according to reports.
Landslide warnings remained in place for 12 provinces on Monday, most of them in the mountainous Andean region.
All but five of Colombia's 32 provinces have been affected since the rains began in March, the government emergencies agency said last week.