Russia has managed to offset lower gas imports to Europe by higher energy prices at its budget revenues from oil and gas jumped by over a third in the first 10 months of the year.

Swedish and Danish authorities have been investigating four leaks from the pipelines in Swedish and Danish exclusive economic zones in the Baltic Sea since they were first spotted.

The Swedish coast guard says Nord Stream 1 has stopped leaking, but an overflight suggests gas is still draining out of Nord Stream 2 and bubbling to the surface over a 30 metre radius.

At the request of Norwegian police, the Norwegian Home Guard, a rapid mobilisation force, began to deploy troops at plants responsible for processing and exporting oil and gas.

A total of four leaks were discovered on the Nord Stream 1 and 2 pipelines in the Baltic Sea near Denmark and Sweden, with a significant fall in gas pressure leading to the detection of the ruptures.

Four days after the leaks were first spotted, it remains unclear who might be behind any attack on the pipelines that Russia and European partners spent billions of dollars building.

The European Union is investigating the cause of the leaks in the Gazprom-run Nord Stream 1 and 2 pipelines under the Baltic Sea and has said it suspects sabotage.

The Europe Union was investigating leaks in the Gazprom-led Nord Stream 1 and 2 pipelines in the Baltic Sea and says it suspected sabotage.

The European Union 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.