At least 52 people were killed and dozens more injured when a landslide swept through a ravine in northwest Colombia after heavy rainfall on Monday.

The landslide struck the municipality of Salgar early Monday morning when most people were sleeping, burying a large part of the town in mud and wreckage. The slide was triggered when a nearby stream spilled over its banks as a result of the rainfall.

Rescue teams and search dogs were continuing to comb through the debris, looking for the missing and injured.

"We don't know how many people are missing," said Colombian President Juan Manuel Santos, who made a visit to the disaster zone Monday to meet with local authorities.

The death toll from the landslide is predicted to rise

Additional rainfall has residents on edge.

"We're on alert because there are fears there could be another landslide," resident Maria Gutierrez told local media, according to Reuters.

Mayor Olga Osorio said the death toll could continue to rise - perhaps even double - given the number of injured and missing people.

"The homes and buildings on a stretch of at least 10 kilometers [about 6 miles] along the stream have been completely destroyed," she said.

Locals have demanded humanitarian aid in Salgar, a municipality of about 20,000 people, since the landslide and flooding has left residents without drinking water and other public services.

Colombia's mountainous terrain and rainy climate make it especially prone to landslides and flash flooding. In 2010-2011 more than 1,300 people were killed and 100,000 homes destroyed in landslides and flooding.

bw/cmk (AFP, Reuters, dpa)