Sections of two telecom cables were cut on November 17 and 18 in Swedish territorial waters. Suspicions have been directed at the Yi Peng 3, which according to ship tracking sites had sailed over the cables around the time they were cut.

The Yi Peng 3 had been anchored in the international waters of the Kattegat strait between Sweden and Denmark.

Ship tracking site Vesselfinder showed the Yi Peng 3 heading north out of the strait on Saturday.

Beijing on Monday confirmed the ship had left "to ensure the physical and mental well-being of the crew".

"The shipowner company, after a comprehensive evaluation and consultation with relevant parties, decided to resume operations," foreign ministry spokeswoman Mao Ning said.

"China has notified all relevant countries in advance," Mao said.

"China is willing to maintain communication and cooperation with the countries involved to advance the follow-up handling of the incident," she added.

- Observers -

However, Swedish Foreign Minister Maria Malmer Stenergard also noted Monday that Swedish prosecutors had not been allowed to conduct an investigation.

"Swedish police have been on board as observers in connection with the Chinese investigation... At the same time, I note that China has not heeded our request for the prosecutor to conduct an investigation on board," Stenergard said in a statement to AFP.

On Thursday, authorities from Sweden, Germany and Finland were invited aboard as observers for an investigation led by China.

A Danish representative also accompanied the group as the country had served a "facilitating role" by hosting meetings between the countries earlier in the week, its Foreign Minister Lars Lokke Rasmussen had said.

Prosecutor Henrik Soderman, told AFP that no measures could be taken on board the ship as part of the Swedish judicial probe, including questioning crew members or technical investigations.

- 'We have been clear with China' -

"Our request that Swedish prosecutors, together with the police and others, be allowed to take certain investigative measures within the framework of the investigation on board remains. We have been clear with China on this," Stenergard said.

Sweden in late November requested China's cooperation in the investigation, but Prime Minister Ulf Kristersson stressed that there was no "accusation" of any sort.

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 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.