A joint investigation by Finland and Estonia into damaged infrastructure in the Gulf of Finland suggests a fault on a communications cable was man made, the State Prosecutor's Office on Thursday.
Last week, officials said damage to the Balticconnector gas pipeline and a data cable owned by telecommunications company Elisa are being investigated as sabotage.
It is known that two ships were in the area around the time the faults were discovered.
"In the course of the investigation, we have analyzed the movement of ships that were taking place in the area at the time. We have also identified that one vessel flying the flag of the Russian Federation and another flying the flag of Hong Kong were in the area at the time," state prosecutor Triinu Olev told "Aktuaalne kaamera".
She said the evidence gathered so far shows the damage to the cable was made by people. But the investigation still needs to confirm the intention behind it.
"Currently, in the case of the communication cable between Estonia and Finland, it has been established that it is not natural damage, and based on the currently collected evidence, there is reason to believe that it is man-made damage. However, during further proceedings we find out whether it is deliberate damage or an action caused by some kind of negligence," Olev said.
The prosecutor's office is exploring different possibilities and checking all circumstances.
The government has said, as the primary evidence has already been collected, that repairs can start as soon as possible. Ideally, next week. The repair vessel has been helping to collect evidence and locate the damage.
Both Estonian and Finnish investigators are aware of the ships that were in the area and are working to establish if there is a connection.
But it is too early to attribute blame and say whether the damage was made deliberately with the intent of damaging critical infrastructure, a statement said.
Investigators are also exploring the evidence for the damaged Estonian-Swedish communication cable, named as the EE-S 1 by Swedish broadcaster SVT. Preliminary data indicates it could have been man-made but further checks need to be carried out.
The government said there are backup communications cables available if undersea cables break.
On October 8, the 77-km Balticconnector gas pipeline between Finland and Estonia experienced a sudden drop in pressure, which experts believe could only be attributed to a leak. A damaged communications cable was also found.
Finnish sources pointed the finger at Russia.
Earlier this week, Stockholm reported that a fault was discovered on a cable between Estonia and Sweden. The Estonian Ministry of Economic Affairs said preliminary information suggests it is not connected to the other two incidents.
Editor: Merili Nael, Marko Tooming, Helen Wright