Russian Foreign Ministry says Washington's intelligence agencies have "full control" over the waters around Denmark and Sweden, where the leaks occurred.

The Nord Stream pipelines, affected by the leaks, are operated by a consortium majority-owned by Russian gas firm Gazprom.
The Nord Stream pipelines, affected by the leaks, are operated by a consortium majority-owned by Russian gas firm Gazprom. (AA)

Russia's foreign ministry has said ruptures to the Nord Stream pipelines that have caused gas leaks off the coasts of Denmark and Sweden occurred in territory that is "fully under the control" of US intelligence agencies.

Thursday's remarks came as a fourth leak on two Baltic Sea gas pipelines between Russia and Europe was reported off southern Sweden. All four detected leaks are in international waters, two near Sweden and two near Denmark.

The Nord Stream 1 and 2 pipelines have been at the centre of geopolitical tensions in recent months as Russia cut gas supplies to Europe in suspected retaliation against Western sanctions following its military offensive against Ukraine.

Russian Foreign Ministry spokesperson Maria Zakharova told a broadcast on Thursday that Washington had "full control" over the waters around Denmark and Sweden.

"It happened in the trade and economic zones of Denmark and Sweden. There are NATO-centric countries," Zakharova said an interview with the Soloviev Live online broadcast on Thursday.

"They are countries that are completed controlled by the US intelligence services."

Denmark is a member of the NATO military alliance, while Sweden's membership is pending after it abandoned its historic policy of non-alignment following Russia's offensive against Ukraine.

Zakharova did not provide evidence of US control over Sweden and Denmark. Russia frequently rails against American influence and military support for Europe.

READ MORE: Sabotage suspicion grows stronger after Nord Stream blast reports

Sabotage suspected

Swedish news agency TT reported on Thursday that a fourth leak had been reported off southern Sweden. The country's coast guards told the news agency that they have a vessel on the site of that leak.

The Danish and Swedish governments believe that the leaks off their countries were “deliberate actions.” Ukraine alleges the leaks are the result of a "terrorist attack" by Moscow.

The European Union, too, suspects sabotage was 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.

The Kremlin says it is "stupid and absurd" to suspect that Russia was behind gas leaks and adds that it is "quite problematic" for Moscow that the expensive "this gas is disappearing into the air".

While neither pipeline was in use at the time of the suspected blasts, they were filled with gas that has been spewing out in the Baltic Sea since ruptures were first detected on Monday.

Explosions were recorded before the leaks. A first explosion was recorded by seismologists early Monday southeast of the Danish island of Bornholm.

A second, stronger blast northeast of the island that night was equivalent to a magnitude-2.3 earthquake. Seismic stations in Denmark, Norway and Finland also registered the explosions.

The Gazprom-led Nord Stream 1, which has an annual capacity of 55 billion cubic metres, was halted on August 31 for what Gazprom said would be three days of repair work.

Gazprom failed to restart flows, however, saying it was unable to carry out the required work due to Western sanctions imposed on Moscow.

In parallel to the Nord Stream 1 pipeline, Nord Stream 2 was intended to double the capacity for Russian gas imports to Germany. But Berlin blocked newly completed Nord Stream 2 in the days before the Ukraine conflict erupted.

READ MORE: Sabotage cannot be ruled out as reason for Nord Stream leaks: Kremlin

Source: TRTWorld and agencies