MOSCOW—Russia’s embassy in the United States on May 11 rejected speculation that Moscow had any responsibility for a ransomware cyberattack that has disrupted activity at the biggest U.S. gasoline pipeline.

President Joe Biden on May 10 said there was no evidence thus far that Russia’s government was involved, but said there was evidence that the culprits’ ransomware was in Russia.

The Colonial Pipeline will not resume full operations for several days due to the attack, one of the most disruptive digital ransom schemes every reported which has been blamed on a shadowy criminal network called DarkSide.

“The Embassy took note of the attempts of some media to accuse Russia of a cyber-attack on Colonial Pipeline,” the Russian embassy said in a statement on Facebook.

“We categorically reject the baseless fabrications of individual journalists and reiterate that Russia does not conduct ‘malicious’ activity in the virtual space.”

The FBI attributed the cyberattack to DarkSide, a group believed to be based in Russia or Eastern Europe. Its ransomware targets computers that do not use keyboards in the languages of former Soviet republics, cyber experts said.

The pipeline shutdown will reduce fuel availability in the near term, push up prices and force refiners to cut production because they have no way to ship the gas.

Russia, one of the world’s major gasoline producers, is considering banning gasoline exports to combat rising fuel prices domestically, a move that could further strain fuel availability in the United States, already hit by the pipeline shutdown.