More than two years after a military junta seized control of Myanmar in a coup, an internal conflict is escalating into ever more savage territory, leaving a trail of decapitations and dismembered bodies that rights groups say could constitute war crimes.

Myanmar Witness, a team collecting and investigating evidence of possible rights violations across the Southeast Asian country, published a report Friday that offers a rare independent confirmation of atrocities against suspected resistance fighters – and possibly civilians – in villages across the Sagaing region, a hotbed of resistance to the junta.

The incidents “show a pattern of excessive violence by the perpetrators, including beheadings, dismembering and torture,” the report says. “As the beheadings serve no functional purpose, they represent a dramatic and horrific warning to those resisting military rule.”

The findings suggest that the fighting has taken a barbaric turn, even for a country that – apart from a short interlude under a civilian-led government – has been ruled with brutal force by a junta for half a century.

According to Myanmar Witness, a military column traversed the Sagaing region between late February and early April, perpetrating a spate of beheadings, mass killings, fires, rapes and raids in several villages.

The report’s authors could not definitively link the junta’s forces to all of the incidents but were able to establish their presence in the area through military statements, reports in pro- and anti-junta news and social media outlets and geolocating drone footage of some of the alleged incidents. The proximity of the villages – all within walking distance – “increases the probability that the same forces were responsible for the incidents,” the authors write.

In one such episode, troops raided a village in Myinmu township, about 45 miles west of Mandalay, on Feb. 26, according to pro- and anti-regime news outlets. The next day, several corpses were found in the area, at least one with its head severed, according to images shared by the outlets. The deceased were reportedly members of the People’s Defense Force, local militias loyal to the ousted government. Myanmar Witness used geolocated user-generated content and satellite imagery to pinpoint the location of at least one of the dismembered bodies and to show that the area had recently been damaged by fire.

Another incident detailed in the report involved an alleged mass killing in a village in Sagaing township in early March. The bodies of a number of local people – media reports said there were 15, including three women – were found on a river bank, Myanmar Witness said. At least one man was found beheaded, according to the team’s analysis of geolocated user-generated content. The group was also able to match images of bodies in a cart to the river location.

In some cases it wasn’t possible to verify whether the beheadings occurred before or after death. But the authors suggested that if it was the latter, as they believed was likely, then the purpose could be to instill fear.

The military junta did not respond to requests for comment Thursday and Friday.

The Tatmadaw, as the Myanmar military is called, has long been known for its brutal tactics in fighting insurgencies and ethnic armed groups, including deliberately targeting civilians seen as their support base. But the recent rise of PDF militias, often armed with little more than homemade weapons and local knowledge, has triggered a fresh wave of violence. The military has ratcheted up an increasingly bloody counteroffensive, launching airstrikes, burning villages and terrorizing those opposed to its power grab.

Leaders of the Association of Southeast Asian Nations expressed their deep concern over the ongoing violence in Myanmar at a gathering in Indonesia this week. They called for an “immediate cessation” of clashes following a weekend attack on an aid convoy delivering supplies to displaced residents. The regional group continues to engage with the junta, though the regime is barred from sending representatives to high-level ASEAN meetings.

The depravity of the recent attacks has drawn parallels with the carnage perpetrated by Russia’s military elsewhere, including in Ukraine, where war crimes investigations are underway. Russia is one of Myanmar’s biggest allies and has supplied it with military hardware – including jets and missiles – and the two militaries have undertaken joint exercises.

“In addition to buying a lot of Russian kit … I think they’ve absorbed a kind of war-fighting mentality of Russia,” said Richard Horsey, a senior Myanmar adviser with the International Crisis Group. “You don’t have to look far around the world to know what that looks like: Not distinguishing civilians from combatants and using very heavy air power.”

On Tuesday, Human Rights Watch accused the military of using an “enhanced-blast” munition in an airstrike in April as PDF members gathered with residents outside Pa Zi Gyi village in Sagaing to mark the opening of a resistance administration office. The weapons, also known as thermobaric or vacuum bombs, explode in two stages, creating a blast wave that lasts longer than those of conventional explosives.

More than 160 people, including children, were killed in the blast. The military took responsibility for the airstrike at the time but denied that it killed civilians, saying instead that the attack targeted “terrorists.”

Horsey said the junta’s escalating brutality over the past six months is meant to instill “terror and intimidation” in the wider community. “It’s a very symbolic play by the military designed to send a message we will do anything to remain in power,” he said. “The graphic nature of the injuries and the death toll may be part of the point.”