Houses built on the mountainsides of Medellin are especially vulnerable to heavy rains [EPA}

Fears are growing for up to 145 people missing in a landslide in Colombia, which has already claimed the lives of at least 12 people, officials have said.

Emergency crews worked through Sunday night in a bid to rescue those feared missing, clawing through debris after a wall of mud buried around 50 houses in Bello town, near the northern city of Medellin.

The landslide, which struck on Sunday, followed the worst downpours to hit the country in decades, which have left nearly 200 dead and 1.5 million homeless.

"There are 145 people missing, including the 12 dead who have been recovered up until now," Luis
Alfredo Ramos, Antioquia Governor, told reporters in Bello.

According to the Red Cross some 200 emergency workers had been operating in the area in order to save lives.

Weather phenomenon

So far three people have been rescued alive, Cesar Uruena, Red Cross operations deputy director told the AFP news agency.

John Rendon, the emergency management director of Antioquia state, said trained dogs were attempting to locate people beneath tonnes sodden earth.

Authorities are also trying to get heavy equipment to the scene.

Medellin, about 400km northwest of the capital, Bogota, lies in a valley where many poorer neighbourhoods of precariously-built houses are stacked up the mountainsides making them highly vulnerable to heavy weather.

Landslides are common in Colombia's rugged Andes mountains, and rains have been especially heavy this year.

Colombia is experiencing torrential downpours due to the La Nina weather phenomenon, in which cooler-than-normal water circulates in the Pacific Ocean around the equator.

Juan Manuel Santos, the Colombian president, said on Sunday that the number of homeless from the rains could reach two million.

According to the Red Cross, 1,821 homes have been destroyed and another 256,083 damaged due to heavy rainfall and flooding. It has also attributed at least 176 deaths to the season's rains, which have hindered coffee and coal sectors too.

The bad weather has affected neighbouring Venezuela, where driving rains have triggered flooding and cave-ins that have killed 34 people over the past week and left an estimated 90,000 people homeless nationwide.