In the course of investigating the leaks in the Nord Stream gas pipelines, the Swedish Coast Guard has started cordoning off the affected area.
The Coast Guard announced on Monday that ships were prohibited from passing through or dropping anchor within a five nautical mile (9.26 km) radius of the leaks.
In addition, fishing, the operation of underwater vehicles and geophysical exploration are prohibited there until further notice.
The coast guard followed an order from the Swedish public prosecutor with the cordoning off.
The exclusion zone will be set up to enable a "crime scene investigation", the prosecutors said.
They are investigating the suspicion that the leaks in the Russian gas pipelines were caused by sabotage.
At the same time, prosecutor Mats Ljungqvist emphasized that although the investigation was being conducted "intensively", it was still at an early stage.
He could therefore not publish any details about the methods used in the investigation.
Conflicting gas leak reports
A total of four leaks were discovered last week on the Nord Stream 1 and 2 pipelines, which run from Russia through the Baltic Sea to Germany.
All leaks are near the Danish island of Bornholm, two of them in the economic zone of Denmark and the other two in the economic zone of Sweden.
Although the lines are not in operation, they were filled with gas for technical reasons.
The Swedish Coast Guard announced on Monday after an overflight that no more gas was leaking from Nord Stream 1.
On the other hand, gas continues to flow from Nord Stream 2.
On Saturday, the operating company explained that gas was no longer escaping from Nord Stream 2 because the pressure in the pipeline had fallen to the same level as the water pressure.
According to a Danish-Swedish report for the UN Security Council, the leaks were caused by underwater explosions with a yield equivalent to "hundreds of kilos" of explosives.
Both the West and Russia accused it of sabotage.
Russian President Vladimir Putin accused the West of being behind the explosions.