Sections of two telecom cables were cut on November 17 and 18 in Swedish territorial waters of the Baltic Sea off the coast of Denmark.

Suspicions have been directed at a Chinese ship -- the Yi Peng 3 -- which ship tracking sites said had sailed over the cables around the time they were cut, although there is nothing to indicate that it was involved in the incidents.

The Yi Peng 3 has remained anchored in the Kattegat strait between Sweden and Denmark since November 19.

"Sweden has... sent a formal request to China to cooperate with Swedish authorities in order to create clarity on what has happened. That formal request was sent to China earlier today," Prime Minister Ulf Kristersson told a press conference on Thursday.

China's foreign ministry has denied any responsibility in the matter.

"We think it's extremely important to find out exactly what happened and, of course, we expect also China to comply with the request we have sent," Kristersson said.

Kristersson reiterated Sweden's "desire for the ship to move to Swedish waters", and stressed -- as he has done previously -- that it was not an "accusation" of any sort.

Denmark's navy said last week it was shadowing the vessel, which is in international waters. Sweden's coast guard joined it over the weekend.

Swedish and Finnish police have opened investigations and European officials have said they suspect sabotage linked to Russia's invasion of Ukraine.

The Kremlin has rejected the comments as "absurd" and "laughable".

Early on November 17, the Arelion cable running from the Swedish island of Gotland to Lithuania was damaged.

The next day, the C-Lion 1 submarine cable connecting Helsinki and the German port of Rostock was cut south of Sweden's Oland island, around 700 kilometres (435 miles) from Helsinki.

Tensions have mounted around the Baltic Sea since Russia's fully-fledged invasion of Ukraine in February 2022.

In September 2022, a series of underwater blasts ruptured the Nord Stream pipelines that carried Russian gas to Europe, the cause of which has 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.