Russia on Tuesday sentenced a man to six years in prison for vandalizing posters of Russian soldiers decorated as "heroes" for fighting in Ukraine.Moscow has banned criticism of the Ukraine offensive and punished thousands of citizens for denouncing the dragging military campaign.Russia's Investigative Committee said the man's sentence had come into force after he was found guilty of "discrediting" the Russian army under a law used to stifle criticism and vandalism.It did not name him, saying he is a 46-year-old "local" to the central city of Tolyatti, where the posters were damaged.Rights group Memorial identified him as teacher Alexei Arbuzenko."The investigation and the court established that in 2022, the attacker repeatedly damaged posters depicting Russian servicemen who showed heroism in the special military operation," the committee said, using Moscow's name for its offensive.It said he had "involved his minor son" in the act."The court sentenced the attacker to imprisonment for a period of six years, to be served in a general regime correctional colony."The local 63.ru news website in the Samara region published CCTV footage showing two people throwing something at a large billboard on a main road.Memorial says Arbuzenko is a "teacher, psychologist, speech therapist, writer and musician."It said he was sentenced in court behind closed doors, without witnesses or the press.The rights group said Arbuzenko is active in Tolyatti's cultural circles, publishing poems and literature, as well as playing guitar.Russian cities have been heavily decorated with images of troops fighting in Ukraine, with Moscow portraying its long offensive in an exclusively positive light.