During the war the territory of Iran, especially South Azerbaijan, became an important arena of military operations. By the end of 1914, a major part of the Southern Azerbaijan was occupied by Turkish troops. Russian troops by the end of January 1915, Russian troops passed to the offensive, captured Tabriz and soon after could force the Turks out of the South Azerbaijan. To struggle against the Turkish army, the Russian command formed, armed and organized numerous Armenian military units. Invasions during the war of the Russian army together with Armenian armed forces plundered the souks and markets, demolished houses, committed atrocities against Azerbaijanis in Khoy, Salmas, Urmiya, Soujbulaq including other cities.
In early 1918, this massacre took a tragic turn when the Russian moved their troops out of Iran. Taking advantage of a situation, Armenians began committing mass genocide against Azerbaijanis in the northwestern part of South Azerbaijan. In 1918, Turkish troops re-entered the South Azerbaijan and stopped the genocide. Soon after the British Army entered the South Azerbaijan and ethnic clashes stopped detachments of Azerbaijan Democratic Party, headed by Sheikh Mohammad Khiyabani.
The war ultimately resulted in collapse of the economic life of the South Azerbaijan.