“Deep concern” was expressed by Germany and Finland after damage was detected in an undersea telecommunications cable.

“European security is threatened not only by Russia’s aggressive war in Ukraine but also by hybrid warfare by malicious actors,” the two countries’ foreign ministries said in a joint statement.

And in a separate incident, a 218-kilometer-long Internet cable between Lithuania and Sweden’s Gotland Island also stopped working on Sunday morning.

The damage to the 1,170-kilometre-long cable comes at a time of high tensions with Russia, the BBC notes, recalling a series of similar incidents in recent years.

In October 2023 a gas pipeline between Finland and Estonia was severely damaged with Finnish authorities saying it was caused by an anchor dragging a Chinese container ship.

Meanwhile an investigation by German authorities into the explosion on the Nord Stream gas pipeline in the section between Russia and Germany in 2022 remains ongoing, with conspiracy theories rife as some say it was done by Ukrainians, others by Russians and others by Americans.

The cable known as C-Lion1, originating in Helsinki and ending in Rostock, Germany, stopped operating at 4 a.m. Monday.

Finnish network management company Cinia said all internal cables had been cut. “These problems do not happen in these waters without external intervention,” a spokesman for Cinia said.