European countries on Tuesday raced to investigate unexplained leaks in two Russian gas pipelines running under the Baltic Sea near Sweden and Denmark, infrastructure at the heart of an energy crisis since Russia’s invasion of Ukraine.

Several European officials said sabotage appeared to be the likely cause, while Russia — which built the network — did not rule it out.

Norwegian Minister of Petroleum and Energy Terje Aasland said Tuesday that the initial information received about the leaks indicated “acts of sabotage.” Swedish Prime Minister Magdalena Andersson and her Danish counterpart, Mette Frederiksen, both said the incident was likely “deliberate” but played down the possibility of a military threat.

In Moscow, Kremlin spokesman Dmitry Peskov told reporters,” “No option can be ruled out right now.”

Both pipelines have been flashpoints in an escalating energy war between European capitals and Moscow that has pummeled major Western economies, sent gas prices soaring and sparked a hunt for alternative energy supplies.

According to pipeline operator Nord Stream AG, it is not currently possible to estimate “a timeframe for restoring the gas transport infrastructure.”

In a statement on Tuesday evening, it added that pressure drops in the pipeline suggested there had been physical damage.

German, Danish and Scandinavian security authorities were closely looking at the leaks in the Baltic Sea and investigating their cause, according to German Economy Minister Robert Habeck, who also said German energy supply had not been affected.

Earlier in the day, Sweden’s Maritime Authority had issued a warning about two leaks in the Nord Stream 1 pipeline, shortly after a leak on the nearby Nord Stream 2 pipeline was discovered.

Neither pipeline was pumping gas to Europe at the time the leaks were found, but the incidents will scupper any remaining expectations that Europe could receive gas via Nord Stream 1 before winter.

“The destruction that occurred on the same day simultaneously on three strings of the offshore gas pipelines of the Nord Stream system is unprecedented,” said network operator Nord Stream AG. “It is not yet possible to estimate the timing of the restoration of the gas transport infrastructure.”

Although neither were in operation, both…