SANTIAGO – An active blaze raging near a Chilean national park, in a region approximately 200 kilometers (120 miles) from Santiago, has grown to be one of the biggest in the country’s history, the government said on Tuesday.

Agriculture Minister Antonio Walker provided that assessment after flying over the affected zone, which now covers an area of more than 5,200 hectares (20 square miles).

A National Forest Corporation (Conaf) report said Tuesday that firefighters are working to prevent the blaze surrounding the Radal Siete Tazas national park from consuming vegetation inside that protected area.

Some 500 firefighters, divided into a total of 26 brigades, have been deployed to battle the blaze, Walker said.

Seven planes and 11 helicopters also are being used in the firefighting effort, as well as more than a dozen machines on the ground.

The Conaf said the fire was between low and medium intensity and was spreading at a low to medium velocity.

The region near the town of Molina – in the Maule region – is under red alert, with the national park closed as a preventive measure and 150 people evacuated from two nearby inhabited areas.

The fire has not yet affected Radal Siete Tazas’s vegetation, but the park has been closed to visitors due to a “dense cap of smoke” that could affect visibility and cause an accident, the Conaf said.

Radal Siete Tazas is an area designated for protection and conservation due to its valuable ecosystems and the native species of flora and fauna it harbors, as well as being a zone used for outdoor recreational activities.

Conaf Director Jose Manuel Rebolledo told local media on Monday that the blaze poses a particularly complicated challenge due to the “very abrupt topography that results in a situation in which trees that are burning up above fall down and start new fires.”

In 2017, forest fires in Chile caused 11 deaths, destroyed 1,603 houses and torched roughly 600,000 hectares (2,316 sq. miles), a situation that experts described as one of the worst tragedies in the history of that South American country.