A fourth gas leak has been found on the damaged Nord Stream pipelines by Sweden's coast guard.
The pipelines running from Russia to other parts of western Europe have suffered leaks this week which are suspected to have been caused by sabotage.
They have been flashpoints in an escalating energy war between capitals in Europe and Moscow that has damaged major Western economies and sent gas prices soaring.
As gas continues to pour out into the Baltic Ocean for a third day after first being detected, it remained unconfirmed who is responsible for any sabotage on the pipelines that Russia and European partners spent billions of pounds building.
Russia, which slashed gas deliveries to Europe after the West imposed sanctions over Moscow's invasion of Ukraine, has also said sabotage was a possibility.
It has now emerged that there is a fourth leak, according to a spokesperson for the Swedish coast guard.
"Two of these four are in Sweden's exclusive economic zone," coast guard spokesperson Jenny Larsson told the newspaper Svenska Dagbladet.
The two other holes are in the Danish exclusive economic zone.
The European Union suspects sabotage is behind the gas leaks on the subsea Russian pipelines to Europe and has promised a "robust" response to any intentional disruption of its energy infrastructure.
"Any deliberate disruption of European energy infrastructure is utterly unacceptable and will be met with a robust and united response," the EU foreign policy chief Josep Borrell said.
Echoing the views of Germany, Denmark and Sweden, he said sabotage was likely, although the EU has not named a potential perpetrator or suggested a motive.
Washington, which has led efforts to punish Moscow over the war, believes its too soon to conclude there was sabotage, a senior US military official said.
"The jury is still out," the official told repoters. "Many of our partners, I think, have determined or believe it is sabotage. I'm just - I'm not at the point where I can tell you one way or the other."
The UN Security Council will convene on Friday at the request of Russia to discuss damage to the pipelines, the French UN mission, which holds the presidency of the 15-member council for September, said.
Russia's embassy in Washington said Moscow had asked for the meeting as it "insists on the need for a comprehensive and objective examination of the circumstances of the unprecedented attacks on Russian pipelines".
The embassy, in an early Thursday statement on its Telegram channel, also accused the United States of attempts to "squeeze out" Russia from the energy market through "non-market methods and sanctions."
