Finnish authorities have boarded a foreign oil tanker escorted into its waters after disruptions on a subsea power link and several data cables.

The police and border guard boarded the vessel, Eagle S, for investigations. The ship, sailing under the Cook Islands flag, was observed to be missing its anchor, Finnish authorities said at a news conference Thursday. The anchor is believed to have caused the damage, they said.

On Wednesday, a 105-mile subsea electricity line connecting Finland and Estonia went offline. Since then, four underwater data cables have also been experiencing disruptions.

It’s the third such incident in just over a year. Last month, a high-speed fiber optic cable in the Baltic Sea connecting Finland and Germany was severed by what was likely an external impact and a nearby link between Lithuania and Sweden was also damaged, with authorities connecting Chinese bulk carrier Yi Peng 3 to the events. A year earlier, the anchor of NewNew Polar Bear, a Hong Kong-flagged ship, tore up at least two data cables and a gas pipeline.

— The Associated Press