The attack occurred when the officers responded to three false emergency calls, authorities said, adding that the men were attacked in their vehicle with heavy-calibre weapons and burned.

Armed assailants ambushed and killed three law enforcement officers in southern Chile on Saturday before setting their car on fire, authorities said, the latest attack on police to revive security concerns in the South American country.

President Gabriel Boric, in a statement via social media platform X, called the attack in Arauco province’s Canete municipality “cowardly” and declared three days of national mourning to honour the officers.

“Today the entire country is in mourning. There is heartbreak, sorrow, anger. But these emotions do not paralyse us, they force us, they mobilise us. We will find the whereabouts of the perpetrators of this terrible crime,” wrote Boric, who travelled Saturday to where the attack took place.

Authorities said the officers – identified as Sergeant Carlos Cisterna, Corporal Sergio Arevalo, and Corporal Misael Vidal – responded to three false emergency calls and were attacked in their vehicle with heavy-calibre weapons. They were burned inside the armoured patrol vehicle on a road near the city of Concepcion, some 400km (about 250 miles) south of the capital Santiago.

Boric, who travelled to the area with a large contingent including top military and congressional officials and the president of the Supreme Court, offered condolences to the victims’ families and vowed that the killers would be found and brought to justice.

“There will be no impunity,” he said in his statement after firefighters dousing the burning police car made the grisly discovery. Boric described the assailants as “terrorists”.

It remains unclear who carried out the attack on Chile’s national police.

The region where the killing took place is home to long-running conflict between the Mapuche Indigenous people and landowners and forestry companies. The conflict has intensified in recent years and forced the government to impose a state of emergency and deploy the military to provide security.

About one in 10 citizens in Chile identify as Mapuche, the tribe that resisted Spanish conquest centuries ago and was defeated only in the late 1800s after Chile won its independence. Large forestry companies and farm owners control large tracts of land originally belonging to the Mapuche, many of whom now live in rural poverty.

Saturday’s killing had been well planned, early reports suggest. Hundreds of people gathered outside the presidential palace in Santiago to protest against the attack, which coincided with National Police Day, celebrating the 97th anniversary of the establishment of the Carabineros –Chile’s military police force. It was the second such fatal attack on the force this month.

The Carabineros’ general director, Ricardo Yáñez, told reporters the officers had been dispatched in response to fake distress calls from the rural road, where they were met with a barrage of gunfire.

“This was not coincidental, it was not random,” Yáñez said of the ambush.

The spate of bloodshed has tested Boric, who came to power in 2022 promising to ease tensions in the region, where armed Mapuche activists have been stealing timber and attacking forestry companies that they claim invaded their ancestral lands.