Emergency crews used helicopters Thursday to rescue some of the nearly 100,000 people hit by the worst rains in three decades in southern Chile, where at least four people have died, officials said.

A storm has dumped torrential rain on the Araucania region 700 kilometers (435 miles) south of Santiago since Saturday, damaging at least 10,000 homes as waters flooded rivers and canals, blocked roadways and inundated 200,000 hectares (494,000 acres) of farmland.

The towns of Carahue, Nueva Imperial, Puerto Saavedra and Teniente Schmidt were all inundated after nearby rivers overflowed.

In Araucania, a largely rural region that is home to indigenous Mapuche tribes, about 1,400 people were placed in emergency relief centers, while another 12,373 people were cut off by rising floodwaters as emergency personnel were conducting evacuations by helicopter.

Of the four known fatalities, one woman was crushed when her house collapsed, while the three other victims drowned, according to the National Emergency Office.

The region was designated a "catastrophe zone" by President Michelle Bachelet, who toured some of the worst-hit areas Wednesday.

The rains had eased mid-week, although a new storm front is expected to batter the region on the weekend.