Undersea leaks in the Nord Stream gas pipelines were likely caused by powerful underwater explosions on September 26, according to Swedish and Danish seismographic data.

Kremlin spokesman Dmitry Peskov said on September 27 that "it is impossible to exclude any options." 

"Obviously, there is some kind of damage to the pipe; as for what caused it, before there are results of the investigations, no option can be ruled out," Peskov said.

The European Union on September 28 promised a "robust" response to any intentional disruption of its energy infrastructure after saying it suspected sabotage was behind gas leaks discovered this week on subsea pipelines running from Russia to Europe.

U.S. President Joe Biden in February warned that "if Russia invades, that means tanks or troops crossing the border of Ukraine, again, then there will be, there will be no longer a Nord Stream 2. We will bring an end to it." After Biden's remarks, former Polish Minister of Defense, Minister of Foreign Affairs and Marshal of the Sejm of the Republic of Poland Radek Sikorski retweeted the tweet. When the Nord Stream pipeline leaked on Monday, Sikorski again tweeted a picture of the Nord Stream leak on September 28 and said, "Thank you, USA."

The gas leaks from the Nord Stream pipelines will continue until the end of the week, Danish Energy Agency (DEA) Director General Kristoffer Bottzauw said on September 28.