The European Union has broadened the scope of sanctions imposed on Russia over the delivery of gas turbines to Crimea.
Three Russians individuals, including Deputy Energy Minister Andrei Cherezov, and three Russian companies were added by Brussels on Friday to the blacklist of individuals and firms banned by the EU.
The latest additions complement a blacklist that already contains 150 people and 37 firms subject to an asset freeze and a travel ban over the crisis in eastern Ukraine.
Russia has slammed the EU over the fresh sanctions, which prompted "deep regret". Moscow described the EU move against Russia as a "hostile" act. It said the accusations raised by Brussels against Russian officials and companies were "groundless".
"The decision of Brussels to include a number of Russian officials and companies as a retaliatory measure for alleged illegitimate supply of Siemens gas turbines to Crimea prompts deep regret," the Russian Foreign Ministry said in a statement.
Brussels first introduced sanctions on Moscow in 2014, after the Black Sea peninsula of Crimea decided to get separated from Ukraine and rejoin the Russian Federation after holding a referendum in this regard.
The scope of sanctions then gradually expanded as the European Union and the United States kept adding on to the pressure against Moscow over its alleged support for pro-Russian forces in the Russian-speaking Donbass region of eastern Ukraine, who were seeking greater autonomy from the Kiev government.
The latest tightening comes in response to the delivery of Siemens' gas turbines to Crimea in violation of EU sanctions, which bar doing business there since what EU describes as the "annexation."
The EU said the blacklisted companies include Siemens' two Russian contractors that moved the turbines.
Siemens says it has evidence that all four turbines it delivered for a project in southern Russia had been illegally moved to Crimea.
EU's 28 members must be unanimous to go ahead with sanctions which target Russia's energy, financial and arms sectors.
The armed conflict in eastern Ukraine, which was initiated by Kiev after it deployed forces to crack down on pro-democracy autonomy-seekers in the Russian-speaking region, has left more than 10,000 people dead.