2 'dark ships' were spotted near the Nord Stream pipeline leaks days before the explosions were detected, satellite data analysis firm says

• Satellite data analysis firm says there are two ships near the leaks.

• There were 25 ships near the leak sites, two of which had turned off their tracker.

• On international waters, a ship turning off its tracker is a red flag.

According to a satellite data analysis firm, two ships with their trackers turned off sailed near the leak sites of theNord Stream 2 line.

Jerry Javornicky, the founder of SpaceKnow, said that the vessels had their automatic identification systems switched off.

"They had their beacon off, which meant that there was no information about their movement, and they were trying to keep their location information and general information hidden from the world," Javornicky said.

According to Javornicky, SpaceKnow found 25 ships that passed through an area with a several mile radius around the leak sites. According to Javornicky, two of those vessels did not have their information turned on.

The International Maritime Organization requires ships with more than 330 tons of cargo to have their tracker on on international voyages.

A switch off of a transponder is often seen as a red flag, and is a common practice for vessels engaged in illegal activities. The US authorities advise ports to be cautious of ships that manipulate their tracker.

According to Otto Tabuns, the director of the Baltic Security Foundation, it's rare for a ship to turn off its transponder in the Baltic Sea unless it has a secret purpose.

The largest network of natural gas from Russia to Europe is under investigation by Western European countries.

It's not clear who is responsible for the damage caused by several underwater explosions in the Baltic Sea. All of the countries accused of sabotage have denied it.

German officials said shortly after the leaks that they suspected the gas pipes were sabotaged by Russia, while Danes and Swedes said in a letter to the UN that they believed a lot of explosives were used to destroy the pipes.

The findings of all three nations have not been made public.

Business Insider has an article on it.