The Battle of Ushno (16 April 1918) was a military engagement near present-day Oshnavieh, in the West Azerbaijan province of Iran, fought between the Assyrian volunteers led by Agha Petros against the Ottoman Empire, reinforced by local Persian troops and Kurdish tribesmen.
Background
In late March 1918, the Ottomans had in response to the British Invasion of western Iran, dispatched a force to Iranian Azerbaijan in order to occupy both Sauj Bulak (known today as Mahabad) and Ushno.
Persian Cossack troops were dispatched to Urmia and Dilman by the Iranian government in order to disarm the Assyrians. They failed, and the Assyrians continued to carry their arms and maintain their military organization.
Battle
During the middle of April 1918, reports came that an Ottoman Turkish force numbering 2,000, accompanied by Persians, began advancing towards the Assyrian positions in the east from Ushno and Sauj Bulak. Consequently, Agha Petros placed himself in command of the Assyrians in order to advance against the force.
Going over the mountains in Ushno, Petros found the Turks in force, attacked them and defeated them. Following their defeat on 16 April 1918, the Turks were forced to retire from Ushno and Sauj Bulak.
Aftermath
The Assyrians returned to Urmia with 325-350 prisoners of war from the Turkish regular army, 24 of them being officers, besides a large number of Kurdish tribesmen. The prisoners were treated well, and were released within a few days.