RIGA, Latvia (AP) — Swedish prosecutors announced Sunday night that they have opened a preliminary investigation into suspected aggravated “sabotage” and ordered the detention of a vessel in the Baltic Sea suspected of damaging an underwater fiber optic cable connecting Latvia and the Swedish island of Gotland earlier that day.

“Several authorities, including the National Police Operations Department, the Coast Guard and the Armed Forces, are involved in the investigation,” said Mats Ljungqvist, senior prosecutor at the National Security Unit, according to a press release.

The Swedish Coast Guard confirmed to the newspaper Expressen that they were on site near the vessel which the paper identified as the Malta-flagged Vezhen, at anchor near the port of Karlskrona.

“We are directly on site with the seized ship and are taking measures as decided by the prosecutor,” said Mattias Lindholm, spokesperson for the Coast Guard.

According to data from Vesselfinder, the vessel departed from the Russian port of Ust-Luga several days earlier and was navigating between Gotland and Latvia at the time the damage was suspected of having occurred.

Latvia's state-run radio and TV center said Sunday that it recorded disruptions in data transmission on the cable running from the town of Ventspils to the Swedish island of Gotland, and concluded there was a rupture.

The media organization said it was able to operate using other data transmission routes, while it was taking steps to have the cable repaired.

“At the moment, there is reason to believe that the cable is significantly damaged and that the damage is caused by external influences,” Vineta Sprugaine, head of corporate communications at LVRTC, was quoted as saying by the LSM state broadcaster.

Latvian Prime Minister Evika Siliņa wrote on X that her government was “working together with our Swedish Allies and NATO on investigating the incident, including to patrolling the area, as well as inspecting the vessels that were in the area.”

Swedish Prime Minister Ulf Kristersson wrote on X that at least one cable belonging to a “Latvian entity” was believed to have been damaged and that he has been “in close contact” with Siliņa during the day Sunday.

Sunday's rupture follows a string of incidents that have heightened fears of Russian sabotage and spying in the strategic region. There have been previous incidents reported of ruptures of data cables running on the Baltic sea bed, allegedly linked to Russia’s shadow fleet — hundreds of aging tankers of uncertain ownership that are dodging sanctions and keeping oil revenue coming into the country.

Earlier this month, NATO began a new mission dubbed “Baltic Sentry” which included frigates, maritime patrol aircraft and a fleet of naval drones to provide “enhanced surveillance and deterrence” in the Baltic Sea which the transatlantic alliance says is to protect undersea cables and pipelines.