On 26 September 2022, a series of underwater explosions and consequent gas leaks occurred on 3 of 4 Nord Stream pipes, rendering them inoperable. The Nord Stream 1 (NS1) and Nord Stream 2 (NS2) are two of twenty-three natural gas pipelines between Europe and Russia. The leaks were located in international waters, but within the economic zones of Denmark and Sweden. Both pipelines were built to transport natural gas from Russia to Germany through the Baltic Sea, and are majority owned by the Russian majority state-owned gas company, Gazprom.
Before the leaks, the pipelines were filled with natural gas but were not transporting it as a consequence of the Russian invasion of Ukraine. The leaks occurred one day before Poland and Norway opened the Baltic Pipe running through Denmark, bringing in gas from the North Sea, rather than from Russia as the Nord Stream pipelines do.
Russia asked for an international investigation at the UN Security Council which was rejected with 3 votes in favor out of 15. Denmark, Germany and Sweden each initiated separate investigations, describing the explosions as sabotage. The Swedish and Danish investigations were closed in February 2024 without identifying those responsible, while the German investigation was ongoing. On 21 August 2025, the Italian police arrested a Ukrainian man on suspicion of being involved in the sabotage, following European arrest warrants issued by German authorities and on 30 September near Warsaw Polish police arrested another Ukrainian, who had evaded arrest since August 2024. As of September 2025 the German investigation reportedly had identified seven suspects including former members of a private diving school in Kyiv, one of whom has died. In October 2025 the suspect arrested in Poland was released when a Polish court denied the German extradition request. In July 2026, London's High Court ruled against a 579 million Euro insurance claim for the Nord Stream Pipeline reasoning that a war exclusion clause applied with the Russo-Ukrainian war being a significant cause for the sabotage and that a government was behind the sabotage even if no specific perpetrator could be identified.
Background
In 2021, Russia supplied roughly 45% of the natural gas imported by European Union states. The United States has been a major opponent of the Nord Stream pipelines; former US President Donald Trump said in 2019 that Nord Stream 2 could turn Europe into a "hostage of Russia" and placed sanctions on any company assisting Russia to complete the pipeline. In December 2020, then President-elect Joe Biden came out forcefully against the opening of the new pipeline and the impact this would have on potential Russian influence. In 2021, the Biden administration lifted the sanctions, stating that while it was "unwavering" in opposition to Nord Stream 2, removing the sanctions was a matter of national interest, to maintain positive relations with Germany and other US allies in Europe. The second pipeline was completed in September 2021. On 7 February 2022 in a joint press conference with German Chancellor Olaf Scholz, US President Joe Biden said that "we will bring an end to it [Nord Stream]" if Russia invades Ukraine and reemphasised with a promise to do it when asked how, delivering on that promise two days before Russia's 24 February invasion when Germany suspended certification.
Before being sabotaged neither of the Nord Stream pipelines were delivering gas. Nord Stream 2 had been completed in 2021, but had not entered service because Germany had suspended its certification on 22 February 2022 thereby stopping the project, following official recognition of the Donetsk People's Republic and Luhansk People's Republic by the Russian State Duma and President Putin during the prelude to the 2022 Russian invasion of Ukraine. From 31 August 2022, Gazprom had halted delivery via Nord Stream 1 indefinitely, officially because of maintenance.
Both Nord Stream 1 and 2 were however pressurized with gas. The Nord Stream 2 pipeline contained the equivalent of an estimated to of gas, pressurized to over 100 bar, at the time of the explosions.
An environmental impact assessment of NS2 was made in 2019. By 2012, corrosion leaks had only occurred in two large pipelines worldwide. Leaks due to military-type acts and mishaps were considered "very unlikely". The largest leak in the analysis was defined as a "full-bore rupture (>)", for example from a sinking ship hitting the pipeline. Such an unlikely large leak from water depth could result in a gas plume up to wide at the surface.
For NS2, the pipes have an outer diameter of approximately and a steel wall thickness of thickest at the pipe ingress where operating pressure is and thinnest at the pipe egress where operating pressure is , when transporting gas. To weigh down the pipe (to ensure negative buoyancy), a layer of concrete surrounds the steel. Each line of the pipeline was made of about 100,000 concrete-weight coated steel pipes each weighing welded together and laid on the seabed. To facilitate pigging, the pipelines have a constant internal diameter of , according to Nord Stream. Sections lie at a depth of around .
Timeline The Geological Survey of Denmark said that a seismometer on Bornholm showed two spikes on 26 September: the first P wave at 02:03 local time (CEST) indicated a magnitude of 2.3 and the second at 19:03 a magnitude of 2.1. Similar data were provided by a seismometer at Stevns, and by several seismometers in Germany, Sweden (as far away as the station in Kalix north), Finland and Norway. The seismic data were characteristic of underwater explosions, not natural events, and showed that they happened near the locations where the leaks were later discovered. Around the same time, pressure in the non-operating pipeline dropped from , as recorded by Nord Stream in Germany.
After Germany's initial report of pressure loss in Nord Stream 2, a gas leak from the pipeline was discovered by a Danish F-16 interceptor response unit southeast of Dueodde, Bornholm. Nord Stream 2 consists of two parallel lines and the leak happened in line A inside the Danish economic zone. Citing danger to shipping, Danish Maritime Authority closed the sea for all vessels in a zone around the leak site, and advised planes to stay at least above it.
Hours after the German office of Nord Stream had reported pressure loss in Nord Stream 1, two gas leaks were discovered on that pipeline by Swedish authorities. Both parallel lines of Nord Stream 1 were ruptured and the sites of its two leaks were about from each other, with one in the Swedish economic zone and the other in the Danish economic zone. On 28 September, the Swedish Coast Guard clarified that the initially reported leak in the Swedish economic zone actually was two leaks located near each other, bringing the total number of leaks on the Nord Stream pipes to four (two in the Swedish economic zone, two in the Danish).
Danish Defence posted a video of the gas leak on their website which showed that, as of 27 September, the largest of the leaks created turbulence on the water surface of approximately in diameter. The smallest leak made a circle of about in diameter. Analysts noted the much larger plumes as an indication that the rupture is very large, compared to a presumed technical leak plume of .
The SwePol power cable between Sweden and Poland passes near two of the leak sites, and was investigated for damage. Tests by Svenska Kraftnät, published on 4 October, indicated the cable was not damaged.
The Swedish Navy confirmed that its ships had patrolled the area in the days before the explosions, but would not comment on why it had done so. An analysis of AIS-data from MarineTraffic by Swedish media Dagens Nyheter showed Swedish navy vessels in the areas on 21 and 22 September 2022, from five to four days before the sabotage. During the night of the explosions the analysis showed no Swedish vessels in the area.
On 1 October, the Danish Energy Agency reported that one of the two pipelines, Nord Stream 2, appeared to have stopped leaking gas as the pressure inside the pipe had stabilized. The following day, the same agency reported that the pressure had stabilized in both Nord Stream 1 pipelines as well, indicating that the leakage had stopped. In contrast, Swedish authorities reported on 2 October that gas continued to escape from the two leaks in their economic zone, albeit to a lesser extent than a few days before.
The leaks The three leaks that appeared at roughly the same time were relatively close to each other with their gas plumes confined by a exclusion zone straddling the boundary between the economic zones (EEZ) of Denmark and Sweden.
The distance between the southern- and northernmost leaks is .
+ 26 September 2022 Nord Stream leaks Pipe EEZ Coordinate Time CEST Richter scale Distance to land Discoverer NS2 pipeA Denmark 02:03 2.3 km (roughly southeast of Dueodde Lighthouse) Danish F-16 interceptor response unit NS2 pipeA Sweden 19:03 2.1 km (east of Simrishamn) Swedish authorities. Second leak on that pipe, initially reported as a single leak with NS 1 Pipe A NS1 pipeA Sweden 19:03 2.1 km (roughly south of Utklippan) Swedish authorities. Initially reported as a single leak with NS 2 Pipe A NS1 pipeB Denmark 19:03 2.1 km (roughly north-northeast of Svaneke) Swedish authorities
The table's timestamps and Richter scale magnitudes are from seismic data characteristic of underwater explosions and matching the locations of the leaks.
Detection The Geological Survey of Denmark said that the tremors that had been detected were unlike those recorded during earthquakes, but similar to those recorded during explosions each with a magnitude corresponding to a "larger WW2 bomb". The Swedish public service broadcaster SVT reported that measuring stations in both Sweden and Denmark recorded strong underwater explosions near the Nord Stream pipelines. The day after the attack Björn Lund, Associate Professor in Seismology at The Swedish National Seismic Network said "there is no doubt that these were explosions". The German newspaper Der Tagesspiegel wrote that the leaks were being investigated for whether they may have been caused by targeted attacks by submarine or clearance divers.
On 30 September 2022, Denmark and Sweden jointly submitted a letter to the United Nations Security Council stating that the leaks were caused by at least two detonations with "several hundred kilos" of explosives.
According to German Federal Government circles, photos taken by the Federal Police with the support of the navy show a leak long, which could only be the result of explosives.
In the Swedish exclusive economic zone two technogenic (artificial) craters with a depth of were found on the seabed at a distance of about from each other, with pipeline debris located up to away from the explosion sites.
On 18 November 2022, Swedish authorities announced that remains of explosives were found at the site of the leaks, and confirmed that the incident was the result of sabotage.
On 23 February 2023 explosives expert David Domjahn from the Karlsruhe Institute of Technology stated that the four Richter scale tremors would each have to have been caused by C-4 explosive and ruled out the use of shaped charges.