The security of Europe's oil and gas pipelines is at risk after the suspected Nord Stream sabotage. Here's a map of the sprawling network.

• The security of Europe's energy infrastructure is in the spotlight after the Nord Stream damage.
• Norway, now Europe's biggest supplier of oil and gas, is on high alert after acts of "sabotage".

The security of Europe's oil and gas infrastructure is under scrutiny following the discovery of leaks in the Nord Stream pipelines that have further heightened tensions with Russia.

Leaks were found on Monday in the pipelines transporting natural gas from Russia to Europe after a fall in pressure was detected.

On Thursday, Sweden's coast guard said it had identified a fourth leak earlier this week, meaning there were two in the Swedish exclusive economic zone and another two in Denmark's zone.

NATO has warned it could retaliate against what it called "sabotage", while Norway – a member of the military alliance – is planning to mobilize its military around its own infrastructure.

"The military will be more visible at Norwegian oil and gas installations," prime minister Jonas Gahr Stoere said on Wednesday, Reuters reported.

The United Nations Security Council is due to meet on Friday to discuss damage to the pipelines at Russia's request.

Moscow has also said sabotage was a possibility and branded claims that it was responsible for the damage as "stupid".

Norway is now the biggest exporter of oil and gas to Europe, overtaking Russia following the imposition of Western sanctions in the wake of the Ukraine invasion. The Nordic nation has several undersea pipelines running to the rest of the continent, according to the European Network of Transmission System Operators for Gas (ENTSOG), a trade body.

But experts say that also makes Norway, and its Baltic neighbors, more vulnerable to potential sabotage.

"Norway's gas supply is probably the biggest and most strategically important target for sabotage in all of Europe right now," Lieutenant Colonel Geir Hågen Karlsen told state broadcaster NRK, The Financial Times reported.

Norway has more than 5,000 miles of oil and gas pipelines, according to Norwegian Petroleum, making the security task difficult.

"The Norwegian response is understandable," Britain's first sea lord and chief of naval staff Adm Sir Ben Key told The Guardian about Norway's mobilization.

Kay pointed out it wasn't just energy that was at risk of interference. Most of Europe's internet connectivity comes from undersea cables, according to the European Parliament.

"There is a vulnerability around anything that sits on the seabed, whether that's gas pipelines, whether that's data cables that places an obligation on organizations like the Royal Navy – but not just us – to have a means of monitoring and providing security around it," he said.