A fire has destroyed or seriously damaged 1,500 hectares (3,700 acres) of vegetation in a Patagonia nature preserve in southern Chile, forcing the evacuation of 400 people, officials said Thursday.

"We are facing an extremely dangerous and complex fire as we have experienced very hostile climate conditions so far and forecasts say it will stay that way" on Friday, Interior Minister Rodrigo Hinzpeter said.

"The topography is hindering the efforts of rescue workers to reach the area and fight the fire, while the vegetation remains highly combustible."

He said the conditions made it "impossible" to estimate how long it would take to control the blaze.

The fire at Torres del Paine National Park that began on Tuesday near a trail "was very likely caused by human negligence," according to Hinzpeter.

Glaciers and Andean lakes lie alongside natural forests and the Patagonian steppe at the semi-desert nature preserve visited by several thousand tourists each year.

Over 110 Chilean fire workers and forest rangers were battling the fire, along with a couple dozen colleagues from neighboring Argentina. A firefighting support helicopter was due to arrive later in the day, along with 50 additional fire crew members.