Kassa Attack

The Kassa attack (Slovak: Košice attack) was the June 26, 1941 aerial bombing of the city of Kassa, today Košice (Slovakia), then a part of Hungary. This attack became the pretext for the government of Hungary to declare war on the Soviet Union, on 27 June 1941.

On June 26, 1941, four days after Germany attacked the Soviet Union in violation of the Molotov-Ribbentrop non-aggression treaty, three unidentified planes of apparently Soviet origin bombed the city, killing and wounding over a dozen people and causing minor material damage.

The true identity of the attacking nation has never been established. The official explanation preferred by Soviet historians was the idea of a feigned attack by Germany to provoke Hungary into attacking the Soviet Union, employing Soviet planes captured on conquered airfields. Another possibility is that the Soviet bombers mistook Kassa for a nearby city in the First Slovak Republic, which was already at war with the Soviet Union.

After the incident Hungary declared itself at war with the Soviet Union.