In yet another video, the Islamic State has claimed the execution of a Russian spy.

As noted by the New York Times, the video showed a Russian-speaking man confessing to spying for Russia's security service and is then beheaded by what appears to be another Russian-speaking man.

The video began with graphically written Arabic and Russian words, saying, "You will be conquered and humiliated, O Russians."

A bearded man, believed to be in his late 20s, then appears. He identified himself as Magomed Khasayev from Chechnya, and admits to being a spy sent to IS-held territories, with orders to identify fighters who are seeking to return to the Caucasus region to carry out terrorist attacks.

Khasayev admitted to being pressured into working for the FSB to report those who have gone to fight with the Islamic State. He admitted to travelling toTurkey before he was sent by an IS recruiter to Iraq. Still, he remained in contact with his Russian Intelligence handler until he was arrested by the extremist group.

The video then shifts to a beach, with the man kneeling as another stood behind him with a speech for the Russian President, Vladimir Putin.

The man declared that Russians will be killed in retaliation for Russia's strikes against ISIS. He then put a large knife at the throat of the prisoner and proceeds to decapitate him.

The authenticity of the video has not been confirmed yet, and the neither the Russian Foreign Ministry nor their security service has declined to comment on the matter.

According to CNN, if the video is actually authentic, then it is another act of atrocity that the rebel group has broadcast over the years: the terrorist group has broadcast killings of their captives in the past, adding menacing messages for their opponents as well. However, NBC News noted that the execution is the first video of a Russian captive being beheaded, coming just at the heels of a bombing campaign against Syria, which is meant to root out members of the terrorist group.

The war has escalated, especially after Putin vowed to retaliate against the terrorists when they claimed responsibility for the bombing of a commercial jet liner over Egypt at the end of October.

Meanwhile, the executioner in the latest video released by the Islamic State said that the Russian airstrikes "have done nothing but kill peaceful Muslims," which seems to follow the likely death of ISIS Terrorist Mohammed Emwazi, believed to be one of two people "incinerated" in a US airstrike last month in the city of Raqqa.