Swedish maritime authorities have warned of two leaks on Russia’s Nord Stream 1 natural gas pipeline in Swedish and Danish territories.

The leaks, located northeast of Danish island Bornholm, were reported shortly after another report of an overnight gas leak from the non-operational Nord Stream 2 pipeline.

The news comes as European and UK gas futures were up over 4% on Tuesday morning after slumping as much as 15% on Monday as reports of Europe filling its gas storage ahead of schedule.

Benchmark Dutch front-month futures rose 5% to €182 per megawatt hour and the UK natural gas futures GWMV22, +5.91% for October increased by as much as 8% to £260 per megawatt hour (MWh).

“There are two leaks on Nord Stream 1 – one in Swedish economic zone and one in Danish economic zone. They are very near each other,” a Swedish Maritime Administration (SMA) spokesperson told Reuters.

“We are keeping extra watch to make sure no ship comes too close to the site,” said another SMA spokesperson.

Nord Stream AG said in a statement on its website on Monday evening: “Tonight, the dispatchers of the Nord Stream 1 control center registered a pressure drop on both strings of the gas pipeline.

“The reasons are being investigated.”

Authorities suspect the damage was the result of sabotage, with Denmark’s prime minister Mette Frederiksen saying the leaks are “hard to imagine that these are coincidences.”

According to a Reuters report, even Kremlin spokesman Dmitry Peskov has said “no option can be ruled out right now” when asked if the pipeline was damaged through sabotage.

Nathan Piper, head of oil & gas research at Investec, told MarketWatch that the leak has guaranteed a shutdown of gas flows to Germany and increase prices.

He said: “No matter how and why this damage was caused it effectively all but guarantees no Russian gas will flow directly to Germany this winter.

“Near term the impact is limited but as temperatures drop and physical demand for gas for heating increases it is likely to help push up prices into the winter,” he added.

Supply sprint

At the beginning of September, Russian state-owned Gazprom halted gas flows from the pipeline to Germany indefinitely, sending the Dutch TTF gas futures for September to a tail spinning highs of €345.52 per MWh.

EU countries have been sprinting to fill their gas storage capacity ahead of the winter months. Almost 90% of EU gas storage has been filled, according to data from Reuters, ahead of its 80% target by Oct. 1.

Germany, the country with the most reliance on Russian gas flows, has filled its storage to 91% capacity as of Sept. 23.

Deutsche Bank analysts, led by chief economist Stefan Schneider, say one of the main reasons Germany has been able to achieve high storage levels is higher-than-expected energy savings from the industrial sector.

“Savings have reached about 20% in year-on-year terms, exceeding our expectation that the 10% reduction achieved by mid-July would be the upper limit – at least in the short run,” they said in a client note on Tuesday.

The Deutsche Bank team cite a recent BDI survey, where one fifth of questioned SMEs have switched from gas to other sources of energy. However, more than 1/3 are saying that substitution is not an option for them in the short run.