context: The Russians later conceded [3] [4] that the Soviet Union itself had fired an artillery strike, intended to make Finland look like an invader in the Winter War. At that time, Mainila was not within the range of the Finnish artillery because the cannons had been pulled far from the border at the express order of Mannerheim, as the Soviet Union was expected to organize some kind of provocation.
question: Why did the Soviet Union take Mainila shots?
answers.text: intended to make Finland look like an invader in the Winter War