CNN  — 

The images are arresting: Russian fighters aligned with Ukraine crossing the border into Russia’s Belgorod region, seizing a checkpoint and sowing confusion and anger in Moscow.

Residents of the settlements under attack in Russia’s Belgorod region have been resettled in other areas as authorities continue “clearing the territory” after the cross-border incursion that launched in Ukraine, regional governor Vyacheslav Gladkov said on Tuesday.

But questions linger about the groups behind the attack, how it took place, and what it means for the war: Was this a classic piece of a military sleight-of-hand, a brief show of force meant to confuse and distract Russian commanders? Does it signal the emergence of serious armed opposition inside Russia? Or are there murkier forces at work?

Here’s what you need to know.

What has happened in Belgorod?

A group of anti-Putin Russian nationals, who are aligned with the Ukrainian army, claimed responsibility for an attack in Russian’s southwestern region of Belgorod, which borders north-eastern Ukraine.

Russia’s Investigative Committee announced an investigation into the attack on Telegram, claiming: “Residential and administrative buildings and civilian infrastructure were subjected to mortar and artillery fire. As a result of these criminal actions, several civilians were wounded,”

Two areas of the region were then hit overnight by drones, according to regional Governor Vyacheslav Gladkov, causing two houses to catch fire. On Tuesday night, drone attacks sent nine people to hospital, Gladkov said.

A helicopter circles over Russia's Belgorod region, the site of fighting between Russian defectors and pro-Kremlin troops amid the war in Ukraine.

One civilian from the village of Kozinka has died as a result of the cross-border fighting, Gladkov said on Tuesday. He added Wednesday that six districts of the Belgorod region, as well as the city itself, were targeted, but that a counter-terror operation launched in response had been lifted.

About 100 people were evacuated from the Russian border settlements of Glotovo and Kozinka in the Belgorod region, local authorities said.

Aleksey Baranovsky, a representative of the Kyiv-based Russian Armed Opposition Political Centre – the political wing of the Freedom of Russia Legion – told CNN that the operation had started Sunday night and fighting was “ongoing.”

He would not specify the number of fighters who had crossed the border into Russia. Baranovsky said the group wanted to “liberate our motherland from the tyranny of Putin.”

The Russian Ministry of Defense claimed in a daily briefing on Tuesday that its forces repelled attackers back into Ukrainian territory using air strikes, artillery fire and military units. It added: “The remnants of the nationalists were driven back to the territory of Ukraine, where they continued to be hit by fire until they were completely eliminated.”

What did the attackers do?

The attackers appeared to have achieved surprise, apparently taking control of a border post and giving the world dramatic images of Russian nationals actively taking up arms against the Kremlin.

Smoke was also seen rising from apparent explosions in the regional capital of Belgorod, where local authorities confirmed what they described as two drone strikes.

The ground operation was far more ambitious than an incursion earlier this year into Russia’s southern Bryansk region that the Russians blamed on “armed Ukrainian nationalists.”

In a discussion with CNN’s Erin Burnett, retired Army Lt. Gen. Mark Hertling characterised the Belgorod operation as a raid — a surprise attack meant to keep the Russian military on the back foot ahead of a much-anticipated offensive by Kyiv.

A still image shows a flying object exploding in an intense burst of light near the dome of the Kremlin Senate building earlier this month.

“This is all part of shaping operations,” Hertling said. “What occurred today and it’s a magnificent tactic, is these Liberty of Russia Legion or Russian Volunteer Corps, the so-called little green men are going in the opposite direction, they’re trying to free Russian territory.”

“Little green men” was common shorthand for Russian special-forces troops who appeared in Crimea during Russia’s forcible annexation of the Black Sea peninsula in 2014.

Pro-Ukrainian activists on social media are already having a field day, posting memes that compare the Belgorod incident to Russia’s not-so-covert operations to prop up separatists in the Donbas region, joking the attackers would set up a Russian-style statelet called the “Bilhorod People’s Republic.”

Which groups are involved?

The Freedom for Russia Legion said on Telegram early on Tuesday that it and another group, the Russian Volunteer Corps, “continue to liberate the Belgorod region!” The post described the groups as “patriot volunteers” and claimed that Russia was vulnerable to attack as “Russia has no reserves to respond to military crises. All military personnel are dead, wounded or in Ukraine.”

As one of its fighters, who goes by the call-sign “Caesar,” says in a video statement he recorded with his comrades before joining a cross-border raid into his motherland: “Russia will be free.”

CNN’s Sam Kiley interviewed that same fighter in December, while the group was fighting for Ukraine against Russian attacks on the frontline city of Bakhmut.

“From the first day of the war, my heart, the heart of a real Russian man, a real Christian, told me that I had to be here to defend the people of Ukraine,” Caesar said. CNN agreed not to reveal his name to protect his identity.

“It was a very difficult process,” Caesar said of joining the Ukrainian effort. “It took me several months to finally join the ranks of the defenders of Ukraine.”

Now with his family in Ukraine – where he considers them to be safer – Caesar said he was one of about 200 Russian citizens currently fighting alongside Ukrainian troops, against their own country’s armies. CNN has been unable independently to confirm this number.

The Ukrainian government, however, has distanced itself from the Russian fighters, saying they are operating independently in Russia.

“We can confirm that this operation is carried out by Russian citizens,” said Andriy Yusov, Ukrainian Defense Intelligence representative, in a comment to CNN: “In Ukraine these units are part of defense and security forces. In Russia they are acting as independent entities.”

How is the incident playing out in Russia?

As Russian officials condemned the attack, analysts noted widespread confusion in Russia’s information space about how the attack was allowed to take place and how Moscow should respond.

Russian bloggers and pundits reacted with a “degree of panic, factionalism, and incoherency as it tends to display when it experiences significant informational shocks,” the Institute for the Study of War (ISW) think tank wrote in its daily briefing on the conflict.

“The attack took Russian commentators by surprise,” the ISW assessed.

It has the potential to be embarrassing for President Vladimir Putin, who has for 15 months been leading an invasion he baselessly claimed was needed to keep Russia safe. With limited returns on the battlefield, Putin may now face discontent that the war is disrupting life at home.

video thumbnail russia media patriot chance pkg
See how Russian state media is showing latest conflict in Ukraine
03:14 - Source: CNN

Earlier this month, the Kremlin publicized an incident which saw two drones fly above the Kremlin. It remains unclear who was responsible – Moscow blamed Ukraine for what it called an attack on Putin’s life; Ukraine and the US denied any involvement – but the dramatic video could be framed by Putin’s internal critics as a visual example of the unraveling nature of Moscow’s war.

In a separate incident Monday evening, the Freedom of Russia Legion posted a video on Telegram that appears to show the blue and white so-called flag of free Russia flying over Moscow State University.

Other videos posted by the group also appear to show another Russian opposition flag flying over various areas of the Russian capital.

The group did not claim direct responsibility for the incidents and CNN could not independently verify the reports.

What is Kyiv saying?

As has often been the case following supposed violence on Russian soil since Moscow invaded Ukraine, the incident has drawn sharply different accounts from the Kremlin and Kyiv.

Kremlin spokesperson Dmitry Peskov on Tuesday described the instigators as “Ukrainian militants, from Ukraine,” despite the fact that the group claiming responsibility is made up of Russian nationals. Peskov had previously said the Kremlin’s forces were working to push out a “sabotage and reconnaissance group,” according to state media TASS.

A Ukrainian official acknowledged that the units had carried out an operation in the area but insisted they were acting independently.

The Ukrainian National Security Adviser Oleksiy Danilov has told CNN those responsible for the cross border-raid in Belgorod are Russians who want to get rid of “the darkness” in their country, denying any involvement from Kyiv.

“They are Russians, it is their country and they have the right to be there,” Danilov told CNN Senior International Correspondent Frederik Pleitgen in an exclusive interview Tuesday. “There are some Russians who are on the side of the light and who went to deal with the darkness that exists in Russia now.

Danilov rejected accusations of Ukrainian involvement levied by Moscow against Kyiv and said the incident in Belgorod was solely a Russian matter.

Kyiv was, however, given advance warning about the cross-border raid, a Ukrainian defense source told CNN on Wednesday.

It is not entirely clear how the Russian formations fighting on the side of Ukraine are organized and equipped and how they answer to the Ukrainian military’s chain of command.

Some of the fighters appear to be operating up-armored Humvees and Mine-Resistant Ambush Protected vehicles that are apparently of US origin, although the vehicles have been widely exported and sold to different end-users around the globe.

In response to a query from CNN, Ukraine’s International Legion — which incorporates volunteers from around the world — said neither the Russian Volunteer Corps or the Freedom for Russia Legion belong to the International Legion of the Armed Forces of Ukraine.

It’s also a mystery how many fighters the Russian groups can actually muster. Open-source sleuths have scoured recent videos for clues to the identities of some of the individuals who appear to be fighting in Belgorod, including some with apparent far-right and extremist beliefs.

What will this mean for the war?

The attacks are unlikely to force a shift in momentum in the wider war in Ukraine, which has been largely focused in Ukraine’s eastern regions and has seen little territory change hands for several months. The conflict has been in a virtual stalemate and is more likely to be affected by Ukraine’s spring counter-offensive against Russian forces, which may already be underway.

But as with previous flashpoints away from the frontlines, it has the potential to shape the narrative surrounding the conflict in both Russia and Ukraine.

Moscow has always been eager to paint a picture of Russian victimhood as a pretext for ramping up attacks on Ukraine, given its public pretense that the invasion is an act of self-defense and is necessary to keep Russia safe. Putin will no doubt look to use these attacks to bolster that narrative, despite Kyiv’s denials that it had any official involvement.

It is possible that a short-term show of anger may also follow. After previous incidents that have embarrassed Russia – such as the murky drone incident above the Kremlin this month, and the strike on the bridge connecting Russia to occupied Crimea in October – Moscow has responded with a barrage of missile attacks across Ukraine, including on the capital Kyiv.

Putin will likely be eager to focus Russian attention on incidents away from the frontlines, where his forces have been struggling to land a significant blow against Ukrainian defenses – most clearly shown by the months-long, costly effort to capture the relatively insignificant city of Bakhmut.

CNN’s Frederik Pleitgen, Yulia Kesaieva, Allegra Goodwin, Josh Pennington, Florence Davey-Attlee, Victoria Butenko, Anna Chernova, Sam Kiley, Vasco Cotovio, Peter Rudden and Olha Konovalova contributed reporting.