NATO warships have surrounded Yi Peng 3, a Chinese bulk carrier at the center of an international probe into suspected sabotage.

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.