A trial over one of the biggest acts of sabotage in decades is getting underway. Here’s a refresher

Danish Defence Command/Forsvaret Ritzau Scanpix/Reuters

It started with a stream of bubbles rising to the surface of the Baltic Sea.

Seven months after Russia’s full-scale invasion of Ukraine in 2022, explosions burst through two Nord Stream gas pipelines – Russia’s controversial gas highway into Europe – in the waters between Sweden and Poland.

Investigators from several countries raced to determine who was responsible and fingers were immediately pointed at Russia. Then, two Ukrainian nationals were arrested, raising questions about state involvement and presenting a test of loyalty for some of Kyiv’s European allies.

On Wednesday, one of them will go on trial in Germany accused of involvement in one of the biggest – and most mysterious – acts of sabotage in modern history. He denies wrongdoing and Ukraine has denied any involvement.

Here’s what you need to know:

Nord Stream 1 and 2 are two major conduits created to funnel Russian gas to Europe, via Germany.

Owned by Nord Stream AG, whose majority shareholder is the Russian gas firm Gazprom, the pipelines were divisive even before the start of the Ukraine war, mainly due to concerns over European reliance on cheap Russian hydrocarbons.

Nord Stream 1 was announced in 1997, when relations between the West and post-Soviet Russia were relatively calm, and became operational in 2011. Nord Stream 2, a sister project, was completed in September 2021, but never entered service. Germany shelved it days before Moscow invaded Ukraine.

Sean Gallup/Getty Images

In late September 2022, explosions ripped through the two pipelines near the Danish island of Bornholm, releasing plumes of gas into the surrounding water and sparking a cross-border investigation.

Sweden was the first country to sound the alarm on the leaks.

Some experts at the time said they could have been caused by a technical malfunction, but the leaders of several Western countries were quick to identify sabotage as the likely cause.

Two months after the event, Swedish prosecutors announced the incident was a result of “gross sabotage,” adding that “traces of explosives” had been found at the scene.

Although neither pipeline was in operation at the time of the attack, both still contained gas under pressure. As a result, experts said an “unprecedented” amount of the greenhouse gases might have leaked into the atmosphere.

Several agencies were tasked with digging into the attack, including German, Danish and Scandinavian security authorities. European officials vowed a firm response.

European Commission President Ursula von der Leyen said any deliberate act to disrupt Europe’s energy infrastructure was “unacceptable” and would “lead to the strongest response possible.”

Swedish Coast Guard Handout/Anadolu Agency/Getty Images

Germany in particular was keen to see the alleged culprits brought to justice and, in 2024, authorities there issued an international arrest warrant for a Ukrainian man suspected of involvement.

Since then, two Ukrainian men have been arrested over their alleged role in the pipeline attacks.

Denmark and Sweden both closed their criminal investigations into the explosions in 2024, with Sweden citing a lack of jurisdiction and Denmark saying there were not sufficient grounds to pursue the case. This left Berlin the only nation to pursue the leads.

Serhii Kuznietsov, a former Ukrainian soldier , is the lone defendant in the trial starting Wednesday in Hamburg, where he is identified only as Serhii K under German privacy laws.

German prosecutors said he “belongs to a group of people who planted explosive devices in the gas pipelines Nord Stream 1 and Nord Stream 2 near the island of Bornholm in September 2022.”

Prosecutors have accused Serhii K of being an accomplice to the “war crime” of attacking civilian objects, destruction of infrastructure, causing an explosion and disrupting public operations, according to court filings.

The court filings accused him of “acting on behalf of Ukrainian state authorities” in an alleged plot to destroy the Nord Stream pipelines.

His defense lawyer previously told CNN that he denies any wrongdoing.

In 2025, Kuznietsov was arrested by Italian police in Rimini – a city in northern Italy known for its sandy beaches and Roman landmarks – and later extradited to Germany.

Prosecutors in Germany believe he and his accomplices used a sailing yacht to carry out the attack, traveling from the port of Rostock, a city in northern Germany. The vessel had been rented from a German company via intermediaries using forged identity documents, prosecutors claim.

Massimiliano Donati/Getty Images

The second Ukrainian man arrested in connection with the bombing, Volodymyr Zhuravlov, was detained in August in Croatia, where a court has approved his extradition to Germany, Reuters reported last month. His lawyer dismissed the ruling and said he could appeal the decision, Reuters added.

German prosecutors said he was “strongly suspected” of several criminal offenses, including sabotage and causing an explosion, and participating in dives to the pipelines.

Zhuravlov was previously arrested in Poland, which declined to extradite him to Germany.

The explosions rang out at a tense time for Europe.

The attacks heightened the controversy over Europe’s use of Russian gas and put Germany – the driving force behind the gas project – under the spotlight over former chancellor Angela Merkel’s decision to adopt a conciliatory approach to Moscow despite its recent aggression toward Ukraine and Georgia.

Donald Tusk, the prime minister of Ukraine’s close ally Poland, said last year that Europe’s problem was “not that Nord Stream 2 was blown up, but that it was built.”

As far back as 2007, Poland’s then-defense minister Radek Sikorski railed against the Nord Stream 1 pipeline, then under construction, calling it “the most outrageous attempt by Mr Putin to divide and damage the EU.”

When Zhuravlov was initially arrested in Poland, a judge ruled against his extradition to Germany, saying that if the Nord Stream blasts were an act of Ukrainian sabotage, it would be a justified response to an unprovoked invasion.

With court officials saying Wednesday’s trial is expected to run until February next year, Germany will be hoping no new roadblocks lie ahead as it seeks to get to the truth of this murky affair.

CNN’s Sebastian Shukla, Sophie Tanno, Ivana Kottasová, Chris Liakos, Joseph Ataman, Christian Edwards and Rob Picheta contributed reporting.

丹麦国防司令部/Forsvaret Ritzau Scanpix/路透社

一切始于波罗的海海面上升起的一连串气泡。

2022 年俄罗斯全面入侵乌克兰七个月后，位于瑞典和波兰之间的海域，两条北溪天然气管道（俄罗斯通往欧洲的备受争议的天然气通道）发生爆炸。

来自多个国家的调查人员争分夺秒地查明责任人，矛头立即指向俄罗斯。随后，两名乌克兰公民被捕，这引发了人们对国家是否参与其中的质疑，也考验着基辅一些欧洲盟友的忠诚度。

周三，其中一人将在德国受审，他被控参与了现代史上规模最大、也最神秘的破坏事件之一。他否认有任何不当行为，乌克兰方面也否认参与其中。

以下是您需要了解的内容：

北溪1号和2号是两条主要管道，旨在将俄罗斯天然气经德国输送到欧洲。

这些管道由北溪股份公司所有，而该公司的大股东是俄罗斯天然气公司俄罗斯天然气工业股份公司。早在乌克兰战争爆发之前，这些管道就已引起争议，主要原因是人们担心欧洲依赖廉价的俄罗斯碳氢化合物。

“北溪1号”天然气管道项目于1997年宣布，当时西方与后苏联时代的俄罗斯关系相对平静，并于2011年投入运营。其姊妹项目“北溪2号”于2021年9月完工，但从未投入使用。在莫斯科入侵乌克兰前几天，德国搁置了该项目。

Sean Gallup/Getty Images

2022 年 9 月下旬，丹麦博恩霍尔姆岛附近的两条输油管道发生爆炸，大量天然气泄漏到周围水域，引发了跨境调查。

瑞典是第一个对泄密事件发出警报的国家。

当时一些专家表示，这可能是技术故障造成的，但几个西方国家的领导人很快认定，蓄意破坏很可能是造成事故的原因。

事件发生两个月后，瑞典检察官宣布该事件是“严重的破坏行为”，并补充说在现场发现了“爆炸物痕迹”。

尽管袭击发生时两条管道均未运行，但管道内仍充满高压天然气。因此，专家表示，可能有“前所未有”数量的温室气体泄漏到大气中。

包括德国、丹麦和斯堪的纳维亚半岛安全部门在内的多个机构受命深入调查此次袭击事件。欧洲官员誓言将采取强硬回应。

欧盟委员会主席乌尔苏拉·冯德莱恩表示，任何蓄意破坏欧洲能源基础设施的行为都是“不可接受的”，并将“导致最强烈的回应”。

瑞典海岸警卫队供图/阿纳多卢通讯社/盖蒂图片社

德国尤其热切希望将涉嫌罪犯绳之以法，2024 年，德国当局对一名涉嫌参与此案的乌克兰男子发出国际逮捕令。

此后，两名乌克兰男子因涉嫌参与输油管道袭击事件而被捕。

丹麦和瑞典均于2024年结束了对爆炸事件的刑事调查，瑞典方面称缺乏管辖权，丹麦方面则表示没有足够的理由继续追查此案。这使得柏林成为唯一一个继续跟进此案线索的国家。

前乌克兰士兵谢尔盖·库兹涅佐夫是周三在汉堡开庭审理的案件中唯一的被告，根据德国隐私法，他在审判中仅被称作谢尔盖·K。

德国检察官称，他“属于一个在2022年9月于博恩霍尔姆岛附近的北溪1号和北溪2号天然气管道中放置爆炸装置的团伙”。

根据法庭文件，检察官指控谢尔盖·K是袭击平民目标、破坏基础设施、制造爆炸和扰乱公共秩序等“战争罪行”的同谋。

法庭文件指控他“代表乌克兰国家当局”参与了一起破坏北溪天然气管道的阴谋。

他的辩护律师此前告诉 CNN，他否认有任何不当行为。

2025 年，库兹涅佐夫在意大利北部城市里米尼（以其沙滩和罗马地标而闻名）被意大利警方逮捕，随后被引渡到德国。

德国检方认为，他和同伙使用一艘帆船实施了袭击，从德国北部城市罗斯托克港出发。检方称，这艘船是通过中间人使用伪造的身份文件从一家德国公司租来的。

马西米利亚诺·多纳蒂/盖蒂图片社

据路透社上月报道，因涉嫌参与爆炸案而被捕的第二名乌克兰男子弗拉基米尔·茹拉夫洛夫于8月在克罗地亚被拘留，克罗地亚法院已批准将其引渡至德国。路透社还补充说，茹拉夫洛夫的律师驳斥了这一裁决，并表示他可以提出上诉。

德国检察官表示，他“极有可能”犯有多项刑事罪行，包括破坏、制造爆炸以及参与潜水破坏输油管道。

茹拉夫洛夫此前在波兰被捕，波兰拒绝将其引渡到德国。

爆炸声响起之时，正值欧洲局势紧张之际。

这些袭击加剧了欧洲使用俄罗斯天然气的争议，并使作为该天然气项目推动力量的德国成为关注焦点，因为前总理安格拉·默克尔决定对莫斯科采取和解态度，尽管莫斯科最近对乌克兰和格鲁吉亚采取了侵略行为。

乌克兰的亲密盟友波兰总理唐纳德·图斯克去年表示，欧洲的问题“不是北溪2号被炸毁，而是它被建造了”。

早在 2007 年，时任波兰国防部长拉德克·西科尔斯基就猛烈抨击当时正在建设中的北溪 1 号天然气管道，称其为“普京先生分裂和破坏欧盟的最无耻的企图”。

茹拉夫洛夫最初在波兰被捕时，一名法官裁定不准将其引渡到德国，称如果北溪天然气管道爆炸是乌克兰的破坏行为，那么对无端入侵的回应就是正当的。

法院官员表示，周三的审判预计将持续到明年二月，德国希望在查明这起扑朔迷离事件真相的过程中不会再遇到新的障碍。

CNN 的塞巴斯蒂安·舒克拉、索菲·坦诺、伊万娜·科塔索瓦、克里斯·利亚科斯、约瑟夫·阿塔曼、克里斯蒂安·爱德华兹和罗布·皮切塔提供了报道。