Leaders of an activist group of indigenous Mapuche people in Chile on Tuesday denied government accusations that they might have set a forest fire that killed seven firefighters last week.

The fire started Thursday at a private estate in the Mininco Forest near Carahue, about 700 kilometers (440 miles) south of the capital Santiago.

"In the face of accusations issued by persons from the current government and right-wing members of Parliament, we say -- emphatically -- that the CAM (Arauco-Malleco Coordination Group) had nothing to do with events that occurred at the House of Stone estate in Carahue," a statement by the group said.

The group posted the statement -- signed by the group's jailed political spokesman, Hector Llaitul -- on an Internet blog often used by the Mapuche movement. It was then carried by local media.

The CAM is a fringe group of Mapuche land activists that had claimed arson attacks that destroyed a firefighting helicopter and other forestry vehicles on December 30.

The group seeks to reclaim lands in southern Chile they say were taken from them by the government or private owners, such as forestry companies.

"We claim this land as ancestral Mapuche territory taken over by the forestry business, which is why we hold them responsible as the only cause of this tragedy," said the statement.

Immediately after the deaths of the seven firefighters were confirmed, Chilean President Sebastian Pinera said the incident demonstrated "criminal intent" and conduct of a "terrorist nature."

Afterward, Interior Minister Rodrigo Hinzpeter directed suspicions at the CAM and filed a complaint under Chile's anti-terrorism law against the alleged perpetrators of the crime.

After the Mapuche statement was made public, government spokesman Andres Chadwick said Tuesday that it was clear the CAM "does exist. It has an organization, it has its leaders, and it has its actions.

"It claims involvement in some of the fires and says it has nothing to do with others," Chadwick added.

Llaitul, who is serving a 14-year prison sentence for assaulting a prosecutor in 2008, said invoking the anti-terror law was a "political strategy" directed "against the Mapuches."

The Mapuche are Chile's largest indigenous population, making up about six percent of the population.

The US State Department renewed a travel alert Tuesday to American citizens traveling in Chile, warning them to beware of regions that have been struck by forest fires in recent days.

The travel alert mentioned the Magallanes, Maule and Biobio regions as the areas of greatest concern. The Magallanes region was the site of a devastating fire last week in the Torres del Paine national park.

The statement urges US citizens "to exercise caution" when traveling to the Torres del Paine park or any other affected region.