BEIRUT — A Russian disinformation campaign has pushed Syria’s best-known civilian rescue group into the crosshairs of President Bashar al-Assad’s security forces, turning its volunteers into hunted prey, according to a team of open-source researchers and the organization itself.

With the help of Western funding, the Syrian Civil Defense group — more commonly known as the White Helmets — has rescued tens of thousands of civilians from the rubble of Syrian and Russian airstrikes. 

More than 250 volunteers have been killed in the course of that duty, the group’s founder says. Harrowing footage of their missions has often been picked up by international media and broadcast around the world. 

In response, Russia is using state-run bodies and media outlets to mount a “brutal and unrelenting” disinformation campaign against the organization, including bogus charges that the White Helmets are preparing chemical attacks on Syrian soil, the Britain-based Bellingcat research group said Tuesday. 

The campaign “has attempted to cast doubt on their ability to provide evidence, painted them as ‘terrorists’ and ultimately tried to transform them into ‘legitimate targets,’ ” Bellingcat said in a report.

“This isn’t just buzz on the Internet,” said one former White Helmet, who was arrested and tortured by Syrian forces this year and spoke on the condition of anonymity. “It has real-life consequences. We’re dying for this.” 

Since February, the Russian Defense Ministry, the Russian Center for Reconciliation of Opposing Sides in Syria — established to track violence in the war-torn country — and Russian media outlets have published 22 reports alleging that the White Helmets have transported chemical weapons in and around the rebel-held northern province of Idlib in preparation for fresh attacks. 

No such attacks have materialized, and monitoring groups have documented no evidence to support these claims.

 Russia has harnessed disinformation to influence global events ranging from the 2016 U.S. presidential election to Britain’s referendum that year on exiting the European Union. In each case, researchers say, the aim is to muddy the waters, sow distrust and build support for outcomes favorable to Russian interests.

The White Helmets have been first responders during several high-profile chemical attacks by the Syrian military. In the northern town of Khan Sheikhoun last year, rescue workers were also affected when government helicopters dropped a nerve agent on civilians as they slept, causing dozens of men, women and children to die in their beds or in the streets. 

That attack prompted President Trump to launch the first U.S. military action against Syrian military installations since the conflict started in 2011. 

On Tuesday, Bellingcat said almost all of the Russian claims attempting to link the White Helmets to chemical weapons alleged that the group was preparing “false flag” attacks that would provoke the West into attacking the Syrian government again. 

“The extraordinarily low level of evidence supporting these accusations, the absurdity of some of the claims and the continual failure to predict a chemical attack exposes these accusations for what they are: a continuation of a deliberate and planned disinformation campaign against a humanitarian organization operating in the most difficult of circumstances,” said Bellingcat, an investigative journalism platform. 

This month, the State Department said a separate alleged chemical attack in the northern city of Aleppo, first reported in Russian and Syrian government media and blamed on rebel forces, was in fact the work of pro-government forces and involved tear gas, not chlorine. 

Moscow’s military intervention on the side of Assad’s forces in 2015 marked a turning point in Syria’s bitter war. Although politically neutral, the White Helmets have become the best-known public face of the race to save lives in opposition-held areas. 

Founded in 2014 to coordinate rescue efforts across the country as government airstrikes accelerated, the White Helmets have received about $51 million from the British government over five years and roughly  $33 million from the United States. That money has been spent on training for rescue workers, as well as equipment and capacity-building. 

Russian coverage has used those funding streams to depict the group as a stooge of the West, and the media campaign has been accompanied by direct military targeting of White Helmets personnel, equipment and headquarters. 

“Psychologically speaking, it’s had a huge impact,” said Raed al-Saleh, the group’s leader. “Our teams keep asking why we’re not protected, why what we are doing bothers people. But we also know that the very thing that is causing us to be targeted — the fact that we save lives — is also the most important thing we can be doing.”

When pro-government troops retake an area from opposition fighters, White Helmets become hunted men and women. Surrender deals have required signatories to give up the names of local rescue workers. In interviews, former White Helmets who have spent time in government custody have described brutal interrogations in which the claims circulated by Russian outlets — particularly with regard to chemical weapons — are routinely repeated. 

“They went through my phone for hours, checking all the times I’d called my colleagues or I’d spoken with journalists,” said one man recently released from a Damascus detention facility. “Then they told me that they knew I was a White Helmet and that meant execution.”

Interrogators smashed him in the face with a water pipe, then suspended him for days from the ceiling, he said. Reached by telephone in Idlib province, he spoke to The Washington Post on the condition of anonymity because of security concerns.

“They said that we were the ones who brought chemicals to Idlib in order to stage fake attacks there,” he recalled. “They didn’t listen to me. They just kept torturing.” 

Concerns are now mounting for the White Helmets who remain in Idlib, a final opposition stronghold hemmed in by government forces to the south and the Turkish border to the north. 

Earlier this year, in an international operation to rescue the rescuers as government forces closed in, more than 400 of the volunteers and their families were whisked across Syria’s southwestern border into Israel en route to Jordan.

“We deemed the risk they faced then to be a critical one. There may come a time when we have to look at that [kind of operation] again,” a Western diplomat said. “Everyone is concerned.”

Zakaria Zakaria in Istanbul contributed to this report.