WASHINGTON — U.S. intelligence officials warned American defense companies on Thursday to step up security measures following several acts of sabotage in Europe that officials blamed on Russia.

general bulletin In the statement issued by the National Counterintelligence and Security Center, companies involved in defense work, especially those providing support to Ukraine in its war against Russia, were advised to increase their defenses in the face of Russia’s increasing aggression against Ukraine’s allies.

“Russia’s sabotage activities in Europe increase the risk for U.S. companies abroad and potentially at home,” officials wrote in the warning. “Such sabotage operations can sow fear and suspicion, damage critical infrastructure, disrupt commerce, or cause injury and death.”

US and European intelligence officials said Russia has recently carried out numerous acts of sabotage targeting European defense companies, logistics facilities, public service buildings and military installations. Russian intelligence often hires local criminals to carry out acts including arson attacks in the United Kingdom and Poland, officials said.

Earlier this month, security officials blamed Russia for a conspiracy. smuggling incendiary device Cargo planes bound for North America caught fire, one at a courier center in Germany and the other at a warehouse in England.

In addition to disinformation and propaganda, larger hybrid effort Undermining Ukraine’s ability to bolster its allies’ defense against Russian invasion.

Russia denied the allegations. A message left at the Russian embassy in Washington was not immediately returned Thursday.

The National Counterintelligence and Security Center is an institution within the National Intelligence Directorate that focuses on protecting national assets from intelligence threats. Thursday’s bulletin was issued jointly by the FBI and several Department of Defense agencies.