Sweden's prime minister says his government has formally asked China to cooperate in explaining the recent rupture of data cables on the Baltic Sea bed in an area where a China-flagged vessel was sighted.

Multiple countries are investigating and the authorities in Europe say they have not ruled out sabotage. But U.S. intelligence officials have assessed that the cables were not cut deliberately.

A Chinese ship is suspected of severing two critical internet cables in the Baltic Sea in an act of sabotage that may have been orchestrated by Russia.