Flame troopers

 Flame troops' were members of GRU who were trained with flamethrowers.

History
At some point of Tselinoyarsk's formation, the Soviets had stolen various copies of America's M2 Flamethrower system, which was previously used in the Invasion of Guam in World War II. They then started training some of their soldiers in the use of this weapon as well as researching it.

During Operation Snake Eater, after CIA Agent Naked Snake managed to successfully bypass the heightened defenses of Krasnogorje and meet up with EVA, the flame troops were dispatched to locate Snake on Krasnogorje by Colonel Volgin. They were also ordered to prepare their flamethrowers to be fired at Snake if sighted, a job that was also considered a suicide mission as they would rupture their tanks if defeated, as Volgin wanted revenge on Snake for his defeating The Pain, The Fear, and The End.

Behind the scenes
The exact reasons for their being present on Krasnogorje, stated by Sigint, will be different depending on the player's actions beforehand. If the player gets triggerhappy and kills every enemy (s)he sees, it will be implied that the flame troops came to burn Snake under their own volition in order to avenge their comrades. If the player either kills very few enemies or none up to that point, the already stated reason of Volgin dispatching them to fry Snake as revenge for his defeating The Pain, The Fear, and The End will be stated.