The announcement of NATO's increased presence comes from the defense alliance's Secretary General Mark Rutte after a conversation with Finland's President.
"I spoke with President Alexander Stubb about the ongoing Finnish investigation into possible sabotage of underwater cables. I expressed my full solidarity and support," Rutte writes on X.
Stubb: We were quick
The oil tanker Eagle S, suspected of causing the damage, is located in Finnish waters near Porkkala. It was boarded by police and military on Thursday.
We took possession of the ship within a few hours. The response time was faster than a year or a month ago, says Stubb, referring to Finland's actions after previous cable breaks when suspected vessels were able to continue their journey.
The police in Finland say that an air bridge has been created between the mainland and the ship, where technicians are being winched down from helicopters to the ship's deck.
It's a very demanding operation. That's why the investigation is proceeding at its own pace, says Criminal Inspector Sami Paila, according to SVT News, citing Finnish Ilta-Sanomat.
The ship's crew of around 20 people comes from, among others, Georgia and India.
Some will be questioned as suspects, some as witnesses, and for some, it has not yet been determined, says Paila.
Lost contact
Alexander Stubb answers no to the question of whether there have been diplomatic reactions from Russia.
It was at lunchtime on Christmas Day that Finnish network operator Fingrid announced that it had lost contact with the Estlink 2 power cable between Finland and Estonia.
The damage was localized to Finnish waters and suspicions were directed at Eagle S. It is believed to be connected to Russia's so-called shadow fleet, often described as a way for Moscow to circumvent international sanctions.
On Boxing Day, it was discovered that communication cables between Estonia and Finland had also been damaged, likely by the tanker's anchor, where police found "visual evidence".
Estonia's military has sent out a patrol to protect Estlink 1, which is laid on the bottom of the Gulf of Finland.