By Bojan Pancevski and Daniel Michaels

Just after midnight on Dec. 26, a team of Finnish commandos dropped from two helicopters onto the deck of a ramshackle Russian oil tanker in the Baltic Sea and ordered the ship's crew to sail into port.

They were acting on the orders of Finnish officials who suspected the Eagle S had hours earlier dragged its anchor along the seabed to slice through a vital power cable between Finland and Estonia. The Finnish action also potentially prevented the ship from cutting another cable nearby, officials say.

It was the latest incident of suspected sabotage involving ships carrying Russian cargo in the region, and the first time authorities had boarded a suspicious vessel while it was under way.

Then came the real work: finding the evidence to prove sabotage.

Finnish law-enforcement officials questioned the crew and scoured the 750-foot-long ship, digging through its logs and inspecting its anchor, which was torn from its chain during the incident. But Finnish and other officials familiar with the probe say they weren't able to uncover enough evidence to issue arrest warrants or for prosecutors to press charges related to deliberate wrongdoing.

The ship was released on March 2, but three crew members are still under investigation and have to remain in the country, Finland's police said in a statement.

Proving sabotage is difficult and requires significant evidence or testimonies to support the finding, say investigators, prosecutors and officials involved in the investigations. To issue an arrest warrant or bring a case, prosecutors must provide substantial evidence of intentional wrongdoing, rather than an accidental and unnoticed dropping of an anchor.

"Even if you show it was deliberate, it's extremely unlikely you'll find a paper trail linking the incident to a state actor," said Elisabeth Braw, an expert in combat below the threshold of warfare, who is writing a book on subsea geopolitical conflict.

The difficulties of prosecuting such cases are frustrating Western officials who are trying to combat what they say is a hybrid war against critical infrastructure in the West that they blame on Russia.

The Kremlin, which didn't respond to a request for comment, has denied attacks on Western infrastructure in the past.

The North Atlantic Treaty Organization has taken a newly aggressive posture in response to such events in the Baltic, home to a handful of Russia's ice-free commercial ports, and one of the busiest trade corridors in the world. But holding anyone accountable for the incidents is proving hard.

The Eagle S captain told police the Christmastime incident was an accident, according to people familiar with the investigation. Caravella LLC-FZ, the Emirati company which owns the ship, didn't respond to requests for comment.

Having found no link between the damaged cable and the Kremlin or any other government, the Finnish government has released the ship, the people said.

To keep the ship until now, prosecutors have focused on lesser offenses such as environmental and customs violations, these people said.

Captains of other vessels have also blamed mistakes for recent damage their ships are linked to in the Baltic.

In November, the Chinese-flagged Yi Peng 3 was suspected of dragging its anchor for miles along the Baltic seafloor. Western intelligence agencies alleged in private at the time that the captain was acting on the orders of Russian operatives while the ship was moored in a Russian dock earlier that month, The Wall Street Journal reported.

Investigations by German and other European authorities, including a search of the ship that Beijing only permitted to take place on the condition that Chinese officials led it, didn't result in evidence to support that allegation, people familiar with that probe told the Journal.

Beijing didn't respond to a request for comment.

The possibility that the anchor had dropped accidentally is all but ruled out, investigators said, but they added there was a chance that gross negligence or bad weather had played a part.

Investigators established only that the FSB, Russia's largest security service, which also manages the country's borders, held the ship for two days after it was loaded in one of Russia's Baltic ports. They weren't able to find out why it was held. The FSB didn't respond to a request for comment.

Across the world's 450 subsea cable systems, spanning almost one million miles, more than 150 technical faults and other problems occur each year globally, according to the International Cable Protection Committee, a trade group. Up to 80% of cable-damage incidents are caused by accidents linked to commercial fishing and ship anchors, the ICPC said.

Overall trends in accidents are hard to assess but the number of incidents involving severe harm is increasing, said Braw.

Four major Baltic incidents, which damaged undersea cables and a gas pipeline, occurred over the past 16 months. They all involved ships that had been operating between Russian ports or were carrying Russian cargo. The Kremlin has denied wrongdoing.

The incidents prompted NATO to launch a new mission, Baltic Sentry. It is conducting naval patrols and enhanced drone, satellite and electronic surveillance of Baltic Sea areas that are packed with critical infrastructure such as data and power cables, as well as gas pipelines and offshore wind farms.

In the first incident of suspected sabotage, in October 2023, Chinese bulk carrier Newnew Polar Bear cut a data cable and a natural-gas pipeline with its anchor. The ship was allowed to continue its journey despite being under investigation.

The Yi Peng 3 cut two data cables in the same region in the November incident. The Danish navy effectively forced the ship to stop, and China ordered the captain to wait for investigators to board the vessel, which was loaded with Russian fertilizer.

A month later, Finland detained the Eagle S, registered in the Cook Islands, on suspicion it had cut the power cable to Estonia.

On Jan. 26, Vezhen, a Bulgarian bulk carrier that had just departed the Russian port Ust-Luga, was detained and boarded by Swedish special police after damaging a subsea cable, in the first deployment of NATO's Baltic Sentry. The ship was detained and later released by Swedish prosecutors.

The owner said armed Swedish officers "aggressively" boarded the Vezhen.

NATO, inspired by Finland's decisive raid on the Eagle S, will continue acting forcefully to deter attacks on critical infrastructure, said James Appathurai, NATO assistant deputy secretary-general in charge of hybrid warfare.

"The captains and crews of ships that are thinking of acts of sabotage should be aware," he said.

As the U.S. and its Western allies tightened sanctions against Russian energy exports, Moscow started deploying warships to escort its "shadow fleet" of tankers in the Baltic, sometimes including powerful missile ships, according to several European officials.

The Eagle S severed one of the two electricity cables linking Finland and Estonia. The second cable might have been saved from potential damage by the Finnish coast guard's fast action, said retired Dutch admiral Rob Bauer, who recently completed a term as NATO's most senior military official.

"Whether it's bad seamanship or negligence on the part of these ships, or whether it was planned by the Russians...we shouldn't care. This is wrong," said Bauer. "It's a good signal to the Russians and others to see that we are taking action."

After Denmark stopped the Chinese-flagged Yi Peng 3 in November, the ship spent over a month anchored in international waters in the Kattegat Strait between Sweden and Denmark before Beijing allowed investigators aboard.

China cooperated with the investigation, several European officials said. Beijing dispatched a delegation of 19 officers and investigators, of whom 14 came on board together with a team of 19 led by Germany and including European observers, according to a person who was present during the probe. All of the crew members were Chinese nationals.

The probe found that a security mechanism to prevent an accidental dropping of the anchors was operational and had to be manually disabled to drop anchor. The ship log showed the anchor was secured when it left the Russian port of Ust-Luga. The log didn't record the system being disabled or the anchor being dropped mid-journey.

The ship, which is over two decades old, was in very poor condition and the crew appeared disorganized and uncoordinated, the probe found.

The 41-year-old captain first commanded a ship only months before the incident, having served as a senior officer for a decade. He told investigators he and his crew didn't notice the dropped anchor because of high waves, which they blamed at the time for the ship's reduced speed. The captain said he raised the anchor once the weather calmed and he noticed it was down.

When the ship lost nearly half of its speed due to the anchor drag, the automatic pilot switched itself off because it can't operate at speeds below 6 knots, investigators found.

Investigators, who ran a computer model of the incident, found that the ship was sailing in somewhat turbulent weather conditions and that the scenario described by the captain was plausible.

They spent around five hours on board before allowing the Yi Peng 3 to continue, under an agreement with Chinese authorities.

People familiar with the investigation, which is continuing, say they have all but ruled out the possibility the anchor was dropped accidentally. The system that prevents the anchor from dropping accidentally was functioning, they said. One explanation could be gross negligence, they said. Deliberate action can't be excluded, but there isn't evidence to support that, they added.

The eight Eagle S crew members were banned from leaving Finland during the investigation. And the probe shifted focus to the negative environmental impact of the ramshackle ship loaded with Russian oil, manned by Georgian and Indian nationals. Investigators are also looking at potential customs and other violations that fall well short of sabotage, according to the officials.

Investigations into civilian vessels sailing under third-country flags will always face severe diplomatic, administrative and legal challenges, said Nick Thomson, a former CIA paramilitary officer who participated in clandestine naval operations.

Missions such as NATO's Baltic Sentry should be selective because of the high costs and operation requirements, and they should rely instead on more underwater, surface and aerial drones to investigate and deter such incidents, he said.

Write to Bojan Pancevski at bojan.pancevski@wsj.com and Daniel Michaels at Dan.Michaels@wsj.com

(END) Dow Jones Newswires

March 07, 2025 23:00 ET (04:00 GMT)

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