The Istanbul pogrom, also known as the Istanbul riots or September events (Greek: Σεπτεμβριανά Septemvriana, "Events of September"; Turkish: 6–7 Eylül Olayları, "Events of September 6–7"), were organized mob attacks directed primarily at Istanbul's Greek minority on 6–7 September 1955. The riots were orchestrated by the Tactical Mobilization Group, the seat of Operation Gladio's Turkish branch; the Counter-Guerrilla, and National Security Service, the precursor of today's National Intelligence Organization. The events were triggered by the false news that the Turkish consulate in Thessaloniki, in northern Greece—the house where Mustafa Kemal Atatürk had been born in 1881—had been bombed the day before. A bomb planted by a Turkish usher at the consulate, who was later arrested and confessed