Torrential downpours in northern Chile have caused floods and mudslides, leaving hundreds of people in the country's Atacama region isolated.

Chile's National Emergency Office said on Tuesday that 350 people were cut off from the town of Chollay, to the commune of Alto del Carmen and inland.

Local media reported that the Chollay River had burst its banks, causing mudslides in the ravines of Canuto and Zorra Muerta. Forty families are located in the Quebrada Colpe sector and five families in the La Pampa sector.

The landslides prevented emergency workers from accessing the areas worst affected, where cars and roads were completely buried by thick mud and clay.

A red alert has been declared for the region, and the drinking water supply has been interrupted for the whole town of Chollay.

Carmen Bou, the mayor of Alto del Carmen, "the mud is again covering the roads and it's very important for us to have connectivity" with the isolated communities.

Meanwhile, 64 people remain isolated in the region of Tarapaca, due to intense rainfall in nearby mountain ranges.

According to local media, nine people were trapped in the sector of Quipisca, due to roads being flooded.

Dozens of others have also been cut off in the sector of Parca, in the commune of Pozo Almonte and the town of Huatacondo.

The worst of the rain has now passed, and it should become largely dry over the next few days.

Local authorities are now working to clear the roads of slushy mud using heavy machinery.