Wildfires in Chile have left at least 19 people dead, authorities said on Monday, as the government carried out mass evacuations and fought nearly two dozen blazes exacerbated by intense heat and high winds.

While weather conditions overnight helped control some fires, the largest were still active, with adverse conditions expected throughout the day, security minister, Luis Cordero, said at a news briefing on Monday.

"The projection we have today is of high temperatures," Cordero said, and the main worry was that new fires would be triggered throughout the region.

Parts of central and southern Chile were under extreme heat warnings with temperatures expected to reach up to 37 Celsius (99 Fahrenheit).

State of emergency declared in Nuble, Bio bio

As of late Sunday, Chile's CONAF forestry agency said firefighters were combating 23 fires across the country, the largest of which were in regions of Ñuble and Bío Bío, where President Gabriel Boric declared a state of catastrophe.

Over 20,000 hectares (77 square miles) have been razed so far, an area about the size of Seattle, with the largest fire surpassing 14,000 hectares on the outskirts of the coastal city Concepcion.

The fast-moving blaze tore through the towns of Penco and Lirquen over the weekend, destroying hundreds of homes and killing several people, with authorities still assessing the damage.

Heat, blazes also impact Argentina

Authorities are currently battling the fire as it threatened Manzano prison on the edge of Concepcion and the town of Tome to the north.

Both Chile and Argentina rang in the new year with heat waves which have continued into January. Earlier this month, wildfires broke out in Argentina's Patagonia, burning around 15,000 hectares.