Various casualty estimates were made during the operation. The pro-Syrian opposition activist organization the SOHR documented 261 SDF (Syrian democratic forces) and 236 TFSA (Turkish Free Syria Army) fighters were killed, as well as 44 Turkish soldiers, 2 pro-Syrian government militiamen and 139 civilians.
The SCWM site reported the death of 445 TFSA and 429 SDF fighters, 39 Turkish soldiers, 5 pro-Syrian government militiamen and 423 civilians. The pro-rebel Aleppo24 organization claimed 405 SDF and 77 TFSA fighters, 31 Turkish soldiers and 60 civilians were killed by 21 February 2018.
Turkey claimed 2,083 SDF fighters were killed, wounded or captured. Pro-Turkish sources also reported the deaths of 76 TFSA fighters, 33 Turkish soldiers and 9 civilians in Turkey. According to the SDF, 1,219 TFSA fighters and Turkish soldiers were killed, while they themselves lost 177 fighters. The SDF also reported 170 civilians and four pro-Syrian government militiamen were killed.
In January 2018, the Turkish military began an operation in the Kurdish-controlled Afrin District and the Tell Rifaat Subdistrict in Northern Syria. Turkey code-named the operation as Operation Olive Branch (Turkish: Zeytin Dalı Harekâtı). The offensive is against the Kurdish-led Democratic Union Party in Syria (PYD), its armed wing People’s Protection Units (YPG), and Syrian Democratic Forces (SDF) positions surrounding the Syrian city of Afrin. Turkey also says it is fighting ISIL, though ISIL does not exist in Afrin. Afrin and the surrounding area is claimed by the Democratic Federation of Northern Syria as Afrin Canton, part of its Afrin Region. It is the first major military operation by Turkey in Syria since Operation Euphrates Shield.
Turkish President Recep Tayyip Erdoğan has stated that the operation in Afrin would be followed by a push in the northern town of Manbij, which the US-backed Kurdish forces captured from ISIL in 2016. American generals said they will respond “aggressively” if such a provocation is made against them. The YPG announced that it would protect the people of Afrin and respond to the Turkish army. Between 145 and 180 civilians have been reported killed and at least 16,000 civilians have been displaced since the operation started. Other war crime allegations include the mutilation of female corpses by TFSA fighters, the use of chemical gas by the Turkish army, and the indiscriminate shooting of refugees fleeing from the conflict area into Turkey by Turkish border guards.
Erdoğan has threatened there will be a “heavy price” for those who have protested against the military offensive.Hundreds of individuals have been arrested for demonstrating against the operation. Over 800 social media users and nearly 100 politicians and journalists have been arrested for criticizing the operation. Turkish authorities have also arrested numerous leaders and high-ranking members of pro-Kurdish and left-wing political parties.