Kiev, Ukraine and Minsk, Belarus CNN  — 

Security forces shattered the early morning calm of the lakeside Soviet-era resort outside the Belarusian capital of Minsk, bursting in to arrest 32 Russian mercenaries.

It was less than two weeks before Belarus’ presidential election last year, and authorities suspected that the outsiders had been sent from Russia to interfere.

The men were indeed part of a mission. But the target was not Belarus, and they were not under orders from any Russian entity.

They were being set up. The 32, along with one other man detained in southern Belarus, were the target of an elaborate intelligence sting by Ukraine, with the knowledge and alleged support of the United States.

Video released by the Belarusian KGB, State TV and Radio Company of Belarus showed Russian men being detained.

Three former high-ranking Ukrainian military intelligence officials described exclusively to CNN how they orchestrated the extraordinary operation aimed at luring suspected war criminals out of Russia to face prosecution for atrocities committed in eastern Ukraine where separatists backed by Moscow have been fighting for years.

First, the Ukrainian agents posed as a Russian private military company, recruiting for security jobs that paid above the going rate, offering a lucrative $5,000 a month contract to protect Venezuelan oil facilities, CNN was told by the men, who spoke on condition of anonymity because they are not authorized to speak on the sensitive operation.

That bait was taken by hundreds of would-be Russian contractors who applied for work, the sources said, giving Ukrainian intelligence an unprecedented opportunity to begin to identify and reel in those suspected of war crimes.

“We started to call them and say, ‘Hey, man, OK, tell me something about yourself. Maybe you are not really a fighter, maybe you are a plumber or something like that,’” one of the former military intelligence officers told CNN of the vetting calls to applicants.

“And then they started to reveal things about themselves, sending us documents, military IDs and proof of where they’d fought. And we are, like, ‘bingo, we can use that,’” the source added.

In other words, according to the intelligence officers, the targets themselves started to send in evidence of who they were, their military experience and even the particular battles and incidents in which they had been involved, including IDs, and potentially incriminating photos and videos of their exploits in eastern Ukraine and elsewhere.

Remnants of a downed Ukrainian army aircraft lie near Luhansk, Ukraine, in June 2014. Ukrainian officials said it was shot down by pro-Russian separatists, killing all 49 service personnel on board.

One video, shared with CNN by the former military intelligence sources, captures a group of rebel fighters in eastern Ukraine holding up the wreckage of a military aircraft that the sources said had just been shot down, a crime designated as terrorism in Ukraine.

Other applicants linked themselves to the attack on MH17, the Malaysian Airlines flight from Amsterdam to Kuala Lumpur that was shot down in July 2014 over Ukrainian territory controlled by pro-Russian separatists. All 298 people aboard the aircraft died. A Dutch-led team of international prosecutors said the plane was downed by a missile brought in from Russia and fired from a village controlled by separatists. Russia has denied any involvement.

The reconstructed wreckage of Flight MH17 is seen behind presiding judge Hendrik Steenhuis, one of a team of judges and lawyers who assessed the evidence around the tragedy.

“There were two who were present when the missile that downed MH17 was launched. Four others were members of a group responsible for shooting down our military aircraft and killing at least 70 of our best men,” a second former Ukrainian military intelligence source told CNN.

“Identifying and punishing these people was of high interest to us,” he added.

It was apparently of interest to US intelligence too, although US officials deny having a direct role. According to the Ukrainian intelligence officials, the Ukrainian-led operation got US cash, technical assistance and advice from the CIA on how to draw the Russian mercenaries in.

A senior US official told CNN those claims are “false.”

He indicated US intelligence was aware of the operation but denied any involvement. The official, who requested anonymity as he was not authorized to speak publicly, suggested efforts to implicate US agencies may be an attempt to share, or even pass, blame for what was a high-risk Ukrainian operation that went wrong.

CNN spent weeks in Ukraine, verifying and reviewing accounts of the operation and speaking to the men who were on the inside.

Posing as a private military company made sense – military contractors linked to the Kremlin, have become a well-known aspect of life for Russian veterans.

CNN has previously tracked Russian mercenaries operating in Libya, the Central African Republic, Syria and Mozambique among other countries. Often the soldiers-for-hire work for Wagner, a major private military company that’s allegedly linked to Yevgeny Prigozhin, an ally of Russian President Vladimir Putin, though Prigozhin denies the connections. The announcement of the arrests at the Minsk resort by Belarusian authorities said the detained men worked for Wagner.

With their website recruitment ruse going undetected, Ukrainian intelligence officials simply picked those men with the closest and most controversial links to Ukraine and offered them the fake Venezuela contracts, the sources said.

They picked 28 Russians allegedly linked to illegal acts in Ukraine and five more without connections to allay any suspicions, they said.

The Russians were told they would be flown to Turkey for a flight connection to Caracas. The real plan was to get them to Ukraine where they could be arrested, the sources told CNN.

Belarus was seeing tense protests and clashes ahead of the presidential election when the Russians arrived in Minsk.

The coronavirus pandemic threw an unexpected wrench in the plan when Russia closed its borders to stop the spread of Covid-19.

Moscow did, however, continue to permit travel to its neighbor and ally Belarus. According to the Ukrainian sources, the unwitting recruits were transported overland to Minsk by bus, from where they thought they would soon depart for Venezuela.

But once in Minsk, there was a delay. The recruits were told it would be a few days before they could leave and were moved to the Belorusochka Sanatorium, a discreet Soviet-era health resort set on a tranquil reservoir 15 minutes outside the capital, where, the sources said, it was hoped they could remain undetected.

The Russian mercenaries traveled to the Belorusochka resort to wait out a delay, the sources told CNN.

The burly mercenaries at the spa that promises “comfort and coziness” amid the “absence of city fuss and everyday worries” seemed incongruous if not suspicious, one staffer remembered.

“Yes, I remember, I met them,” a security guard told CNN last month. “They spent a couple of days here. They didn’t do anything to disturb us,” he said, adding that the arrests were a surprise. “People come here because there’s a beautiful reservoir on the other side of the sanatorium,” he said.

The lakeside Belorusochka resort is only a short drive from the heart of the Belarusian capital.

The delay was long enough for the Belarusian security services to act, just hours before the group was due to fly out, according to CNN’s sources.

At the time, some suspected Russian involvement. In dramatic scenes, broadcast on Belarusian state TV, the arrested men were paraded on screen, and their identification documents shown as evidence of their Russian military backgrounds.

“We got confirmed intel these Russians had real combat experience, and actually took part in armed conflicts,” an unnamed, heavily disguised Belarusian police commander revealed on state TV.

Belarusian authorities first believed the arrest of the Russians prevented them interfering in the country's presidential elections.

A former presidential adviser in Belarus told CNN on the condition of anonymity that Belarusian authorities initially did believe the group had been sent to Belarus by the Russians to destabilize the country ahead of upcoming elections.

He told CNN there was confusion in Minsk over what seemed to be aggression from their Russian allies.

The Kremlin seemed caught off guard too, with its spokesman telling Russian media they “did not have complete information” about the incident. The Kremlin later denied they had sent the men to interfere in the internal affairs of Belarus.

Ukrainian President Volodymyr Zelensky got involved too, calling for the extradition of the men to Ukraine during a telephone conversation with Belarus President Alexander Lukashenko just days after the arrests.

Belarusian President Alexander Lukashenko, center, attends an urgent security meeting after the arrest of the mercenaries.

“I hope that all suspects in terrorist activities on the territory of Ukraine will be transferred to us for prosecution in accordance with the current international legal documents,” Zelensky said, according to a readout of the call.

A couple of days later, Lukashenko rejected that request. He spoke to Putin and both leaders “expressed confidence that the situation would be resolved,” a Kremlin statement said.

A week on from that call, Russia announced the return of the 32 Russians arrested at the sanatorium. The 33rd man, who was a dual national of Belarus and Russia, stayed in Belarus.

President Zelensky of Ukraine has publicly denied there was a Ukrainian operation, telling Ukrainian TV in June 2021 that his country had been “dragged into” the issue.

“I understand that the idea of this operation was the idea of, let’s say, other countries, definitely not Ukraine,” he said.

Ukrainian officials did not respond to CNN’s request for a comment for this story.

The arrests brought a premature end to the planned sting, Ukrainian officials told CNN.

But according to CNN’s Ukrainian sources, the failure was a serious blow to Ukrainian intelligence who they say had worked on hooking the Russian suspects for close to 18 months.

“If these people would have ended up here in Ukraine, the details of their criminal acts would have become known around the world,” one of the sources told CNN.

“Ukraine could have brought them to justice and shown that our fight with Russia is serious and that we won’t raise our hands in surrender,” the source added.

CNN’s Matthew Chance reported from Kiev and Zahra Ullah reported from Minsk. Katharina Krebs contributed from Kiev.