Under the 28-nation European Union's strict policy of not recognising Crimea's March 2014 annexation from Ukraine.
Under the 28-nation European Union's strict policy of not recognising Crimea's March 2014 annexation from Ukraine, the three individuals will be hit with an asset freeze and a travel ban.
The measures come despite the fact that the EU just days ago bitterly criticised the United States over fresh sanctions targeting Russia for election meddling, on the grounds that it could harm European energy firms.
"The EU has added three Russian nationals and three companies involved in the transfer of gas turbines to Crimea to the list of persons subject to restrictive measures in respect of actions undermining Ukraine's territorial integrity, sovereignty and independence," the EU statement said.
There was no immediate reaction from the Kremlin.
But Ukrainian President Petro Poroshenko said he was "grateful" to the EU, calling the sanctions a "powerful message to the aggressor about unwavering unity and solidarity among the capitals of the European Union."
"Attempts to bypass the sanctions by cynical schemes will lead only to greater price for the aggression. And so be it until the full restoration of sovereignty and territorial integrity of Ukraine, including Crimea!" he wrote on Facebook.
The EU said 153 people and 40 companies had now been targeted by individual sanctions against Russia.
Siemens said last month it was scaling back its Russian operations after finding out that the four turbines had been "illegally" modified and moved to Crimea, which Russia annexed in March 2014.
The new sanctions target Russia's vice energy minister Andrey Cherezov, a senior energy ministry official responsible for electricity projects in Crimea, and the head of a Russian company who led negotiations with Siemens over the original import of the turbines, according to the EU's official legal journal.
The EU said that setting up an independent power supply for Crimea supports its "separation from Ukraine" and that "gas turbines are a substantial element in the development of new power plants."
The turbines had originally been supplied for a power-plant project in Taman, in the Krasnodar region of southern Russia -- separated from Crimea by just a few kilometres (miles) of water.
The companies hit by sanctions are the firm that bought the turbines, the current owner of the machinery, and a firm that specialises in setting up power plants in Crimea.
Siemens had already said last month that it would divest a minority stake in one of the targeted firms, Interautomatika, which sells power-plant control systems.
The German government has expressed anger over the "completely unacceptable" turbine delivery to Crimea and pressed Siemens for answers.
A German government spokesman reportedly said that that Russian President Vladimir Putin himself had personally assured Berlin the turbines would not end up in Crimea.
The EU also maintains broader economic sanctions against Russia, imposed after the shooting down of Malaysia Airlines flight MH17 over Ukraine in 2014.
However sanctions are an increasingly sensitive issue for the EU after the US Congress voted overwhelmingly for fresh measures against Russia, which President Donald Trump reluctantly approved this week.
The EU has said it is ready to retaliate if the US sanctions hurt EU energy firms, amid fears the American measures could interfere with a German-backed pipeline with Russia.
Previous sanctions had all been coordinated on both sides of the Atlantic.