Russian President Vladimir Putin has sent in the feared Spetsnaz special forces to protect the rule of Syrian President Bashar Assad, British newspaper The Mirror reports. 

The Spetsnaz units are prepping to eradicate not just Islamic State (ISIS) fighters, but Western-aligned Free Syrian Army rebels, the website reports.

"Putin's marines are there to guard the airbases they are using against sabotage by rebels," a military source told the Mirror. "But Spetsnaz and air-assault troops are not there to provide security to static objects, they are extremely aggressive and highly trained. They are there to mop up after air strikes, call in air strikes, go on extremely covert missions against rebels and ultimately wipe them out."

Spetsnaz forces are not as accountable as U.S. or British special forces, the source said.

"They are there for one reason, to wipe out anyone threatening Assad. By any means," the source said. "And by doing that they will be consolidating Russia's position on the Med[iterranean Sea] and in the Middle East."

Russia already has been carrying out airstrikes in Syria for the past week. Russia says the strikes are targeting only ISIS positions, but the United States and France say they have instead hit Free Syrian Army positions.

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