By Essi Lehto and Andrius Sytas HELSINKI (Reuters) -Finnish authorities said they boarded and took control of an oil tanker travelling from Russia on Thursday, on suspicion it caused the outage of an undersea power cable and three internet lines connecting Finland and Estonia a day earlier.

Finnish police said on Thursday they are investigating whether a foreign ship was involved in the damage of an undersea power cable connecting Finland and Estonia following a sudden outage on Wednesday.

Finland’s prime minister says authorities are investigating an interruption in a power cable under the Baltic Sea between his country and Estonia.

Finland's Prime Minister Petteri Orpo said on Wednesday authorities in his country were investigating an undersea power cable outage on a line connecting Finland and Estonia.

Head of operations of the Finnish electricity grid tells broadcaster that 'possibility of sabotage cannot be ruled out'

The Finnish national grid operator Fingrid reported damage to the underwater electricity cable Estlink 2, connecting Finland and Estonia. The cause of the malfunction is unknown, Yle reports. It is noted that electricity is not transmitted between Finland and Estonia via Estlink 2 because the cable has been damaged.

By Essi Lehto and Andrius Sytas HELSINKI (Reuters) -Finnish authorities said they had boarded and taken control on Thursday of an oil tanker travelling from Russia, on suspicion it had caused the outage on Wednesday of an undersea power cable and three internet lines connecting Finland and Estonia.

The incident at the Estlink 2 interconnector cable will not affect Finland's power supply, said Finnish Prime Minister Petteri Orpo,