The Shelling of Mainila (Finnish: Mainilan laukaukset) was a military incident on November 26, 1939, where the Soviet Union's Red Army shelled the Russian village of Mainila (located near Beloostrov), declared that the fire originated from Finland across a nearby border and claimed to have had losses in personnel. Through that false flag operation the Soviet Union gained a great propaganda boost and a casus belli for launching the Winter War four days later.[2]