Rescuers on Friday recovered the bodies and continued digging through the mud as nearly 30 people remained missing, said Claudia Helena Velez, a municipal official in Bello, 250km northwest of Bogota.
The landslide, which brought mud, trees, garbage and rocks sweeping through the town of Bello, occurred late on Thursday after five hours of heavy rains loosened the earth in the boulder-covered mountain above town.
At least 11 of those killed were children, said General Ruben Carrillo, police chief of Antioquia state.
About a dozen homes, many made of plywood with tin roofs, were destroyed and entire families were killed by the mudslide.
More than 100 people, including firefighters and members of the civil defence agency, were participating in the rescue effort.
Residents looked for missing loved ones, digging the rubble with shovels and other tools.
Colombian authorities announced a general alert throughout the region, warning that the heavy rains could continue during the weekend.