SANTIAGO (Reuters) - Arsonists in southern Chile burned at least 25 tractor trailer trucks and other heavy machinery early on Friday, according to police and a truck owners association, the largest such attack in months and a sign of heightening tensions in the region.

In a statement following the arson, Chile’s National Confederation of Truck Owners called on the government to “halt the attacks and the terrorism.”

A photo published by the industry group showed several large tractor trailer trucks engulfed in flames along a dark dirt road in the country’s heavily forested Araucania region.

The area is the heart of Chile’s important forestry and paper industry, and the trucks and machinery used by local businesses have often been the target of arson attacks and hijackings.

Individuals and groups claiming to represent the interests of the Mapuche indigenous people have in recent years set fire to fields, forests, vehicles, machinery and residences in the region, leading to deaths and tens of millions of dollars in damage. It was not clear to what extent they have broader support among indigenous communities.

Local authorities had yet to identify suspects as of Friday morning.

“We’re waiting for the prosecutor to arrive and examine the scene,” the governor of Arauco, Humberto Toro, told local radio station radio Cooperativa.

Photos in local media from the scene of one of the attacks showed pamphlets and a banner from a Mapuche organization known as “Coordinadora Arauco-Malleco,” a radical group that says it fights for the recovery of Mapuche lands.

Indigenous communities of south-central Chile have long accused the state and private companies of taking their ancestral land, stripping it of natural resources and using heavy-handed enforcement against their communities.

In January, on the eve of a visit by Pope Francis to Temuco, the regional capital, groups claiming to have ties to the Mapuche set fire to a church, a schoolhouse and three helicopters.