Rainstorms and landslides in Chile have contaminated a major river forcing the authorities to cut off drinking water to four million people in the capital, Santiago.

Officials said the water supply from the Maipo river would be cut to most of the city until the water flowed clear.

People stocked up on bottled water and the authorities ordered restaurants and businesses to remain closed.

Officials also postponed the start of the school term on Monday.

Emergency personnel said the water rushing down from the Andes had also cut roads and isolated thousands of people.

The regional governor of Santiago, Claudio Orrego, said " We are talking about 1.45 million homes that are going to be affected by the cutting off of the water supply, which will be total or partial in 30 districts."

"We still do not know when the drinking water will be turned back on,"

"We cannot guarantee resumption of the service until the River Maipo clears up."

They said the return of water services would depend on weather conditions and storms over the mountains causing heavy rain.

At least four people are known to have died in the floods.

Chile's central region has had months of drought and a series of deadly wildfires which burned for weeks.