BOGOTA (Reuters) - A landslide killed at least four people and left 18 missing in southwest Colombia, authorities said on Wednesday, as the country grappled once again with the deadly pairing of heavy rains and poor infrastructure.

Landslides are common in rural, mountainous areas of Colombia, especially during wetter parts of the year. In April more than 300 people died in a landslide in Mocoa, Putumayo.

Warnings of flash flooding on Tuesday night near the town of Corinto, which sits at the foot of one of the country's Andean ranges in Cauca province, came too late, some residents told local media.

21 PHOTOS Deadly mudslide in Colombia See Gallery Deadly mudslide in Colombia A man holds his son amid a muddy street, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) Colombia's President Juan Manuel Santos walks down a street after floods and landslides, caused by heavy rains where a river overflowed, pushed sediments and rocks into houses and roads, in Corinto, November 8, 2017. Colombian Presidency/Handout via REUTERS ATTENTION EDITORS - THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. Inside view of a destroyed house, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) Residents of Corinto municipality remain in a shelter, after a mudslide due to heavy rains affected their homes in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) Residents remain at their doorstep, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) Residents of Corinto municipality remain in a shelter, after a mudslide due to heavy rains affected their homes in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) A woman and her daughter struggle to walk along a muddy street, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) Residents of Corinto municipality remain in a shelter, after a mudslide due to heavy rains affected their homes in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) Residents of Corinto municipality remain in a shelter, after a mudslide due to heavy rains affected their homes in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) A man takes photos of La Paila river, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) A man stands amid a muddy street, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) A man stands near his destroyed house, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) A man stands near his destroyed house, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) A woman talks on her phone as she holds a shovel to clear the mud from his house, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) People hold shovels to clear the muddy streets, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) A man stands amid a muddy street after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) Men salvage belongings from their houses, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) People hold shovels to clear the muddy streets, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) Colombia's President Juan Manuel Santos walks down a street after floods and landslides caused by heavy rains where a river overflowed, pushed sediments and rocks into houses and roads, in Corinto, November 8, 2017. Colombian Presidency/Handout via REUTERS ATTENTION EDITORS - THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. A young man carries his belongings across a muddy street, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) A woman tries to prevent mud from entering her house, after a mudslide due to heavy rains affected Corinto in Cauca department, southwest Colombia on November 8, 2017 The mudslide hit Corinto on Tuesday night leaving three people dead, 32 injured and 18 missing in addition to hundreds of homes affected, according to the latest balance provided by authorities. / AFP PHOTO / LUIS ROBAYO (Photo credit should read LUIS ROBAYO/AFP/Getty Images) Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

Videos on social media showed water rushing down darkened streets as rain-swollen rivers overflowed and sent mud and rocks down onto buildings.

President Juan Manuel Santos visited Corinto on Wednesday to promise aid to its 30,000 residents, as rescue workers continued to search for the missing.

The government said more than 3,000 people were evacuated from a nearby area before the landslide struck Tuesday evening.

The government will pay rent for those left homeless and help with funeral expenses, Santos said. The local school, which partially collapsed, may have to be relocated, he said.

(Reporting by Julia Symmes Cobb; Editing by Tom Brown)