Georgian servicemen wait before the oath-taking ceremony as the country marks the 100th anniversary of its independence in Tbilisi, Georgia May 26, 2018. (REUTERS PHOTO)

TBILISI, Aug. 6 (Xinhua) -- The Islamic State (IS) militants have threatened to take revenge for the group's members killed by Georgian law enforcers during last year's anti-terrorist operation here, according to local media reports Monday.

A Georgian unit of the terrorist organization said in a video that they will take revenge for their "murdered brothers," Georgian media Palitranews reported while releasing the video.

The report said the video, allegedly made two weeks ago, mentioned the large-scale anti-terrorist operation in Tbilisi in November 2017, during which several IS militants were killed by the Georgian police.

The video did not give specific names, but said, "We remember all this, the killing of our brothers with betrayal and deceit. You will be killed in your homes."

In response, the Georgian State Security Service said Monday that they knew about the video and that a relevant investigation is underway.

Earlier on Monday, the State Security Service announced the detention of a Georgian citizen linked to the IS group who was charged with the illegal purchase and possession of arms.

The State Security Service said that they have also seized an IS flag and other symbols of the terrorist organisation.

Last November, the State Security Service launched a special anti-terrorist operation in Tbilisi, during which three suspects were killed and one was captured.