The cargo ship Vezhen is anchored outside Karlskrona for examination by Swedish authorities
The cargo ship Vezhen is anchored outside Karlskrona for examination by Swedish authorities AFP

Police in Norway said on Friday they had seized a Norwegian-owned ship with a Russian crew over its suspected involvement in damage done to a Baltic Sea cable.

Nations around the Baltic Sea have scrambled to bolster their defences since the suspected sabotage of undersea cables in recent months, with some observers blaming Russia.

The vessel's owner has rejected any wrongdoing. Norwegian police said the vessel was seized at Latvia's request.

The Norway-flagged cargo ship, the Silver Dania, was sailing between Saint Petersburg and Murmansk when a Norwegian coastguard ship stopped it on Thursday evening off the coast of Tromso in northern Norway.

It arrived in the port of Tromso on Friday morning.

"The ship is suspected to have been involved in serious damage to a fibre cable in the Baltic Sea between Latvia and Sweden," police said in a statement.

"Police are now on board the ship to search, carry out interrogations and secure evidence," it said, adding that the crew and shipowner were cooperating with police.

"The entire crew on board is Russian," it added.

Sweden and Latvia announced on January 26 that a fibre optic cable -- owned by Latvia's state radio and television centre (LVRTC) and linking the Swedish island of Gotland to Ventspils in Latvia -- had been damaged.

"The vessel is suspected of having someone on board who played a role in the matter of this cable in the Baltic," Norwegian prosecutor Ronny Jorgensen told a press conference.

He said the damaged cable was an act of "aggravated vandalism".

The Silver Dania is owned by Norwegian shipping company Silver Sea.

The shipowner told AFP the vessel had nothing to do with the damaged cable.

"We sailed near Gotland," Silver Sea boss Tormod Fossmark said, "but we did not cast anchor."

"We did nothing wrong," he added. "Norwegian authorities have brought us into port to clear us of any involvement."

Fossmark said the Russian crew had "sailed for us for a long time".

"They did nothing wrong," he insisted, saying he was "100-percent sure".

Police told reporters at a press conference that the crew, made up of 11 Russians, was cooperating fully and had agreed to detour to Tromso voluntarily.

The Russian embassy in Oslo told AFP by email that none of the sailors had been placed under arrest nor had they contacted the embassy for assistance, adding that it was "following the situation closely".

On January 26, the Swedish coastguard seized a Bulgarian ship, the Malta-flagged Vezhen, off Sweden's southeastern coast in connection with the same cable incident.

Swedish prosecutors have opened an investigation into "aggravated sabotage".

Images of the vessel published by Swedish media appeared to show one of Vezhen's anchors had a broken arm.

Alexander Kalchev, CEO of Navibulgar, the Bulgarian maritime shipping company that operates the Vezhen, denied any involvement.

"I am convinced that we cannot say... that this was a malicious act," he said.

But prosecutor Mats Ljungqvist told Swedish news agency TT on Friday he was confident the Vezhen was involved.

"I think I can say, on very solid grounds, that it is this ship that has damaged the cable," he said.

"Our work is continuing... The ship is still seized and there are various investigative measures being taken, including technical examinations," he said.

The incident is the latest in a series affecting cables in the Baltic Sea, amid heightened tensions between Russia and the West since Moscow's invasion of Ukraine in February 2022.

Finland and Sweden, which both border the Baltic Sea, have dropped decades of military non-alignment to join NATO as concern about the region's security mounts.

Russia had warned both countries of repercussions if they joined the alliance.

In September 2022, a series of underwater blasts ruptured the Nord Stream pipelines that carried Russian gas to Europe. The cause is yet to be determined.

In October 2023, an undersea gas pipeline between Finland and Estonia was shut down after it was damaged by the anchor of a Chinese cargo ship.

In November 2024, two telecom cables in Swedish waters were severed, and on December 25, the Estlink 2 electricity cable and four telecom cables linking Finland and Estonia were damaged.

In mid-January, NATO launched a Baltic Sea patrol mission to secure critical underwater infrastructure.

Frigates, maritime patrol aircraft, submarines and drones are involved in the Baltic Sentry patrols.