According to a statement by the Turkish Armed Forces (TSK), the soldier died on Saturday of injuries sustained during clashes with PKK militants in Nusaybin, a town on the Syrian border.
Also on Saturday, a dozen police officers and a civilian were injured in a PKK bomb attack in the embattled region.
Speaking on condition of anonymity, a security source said PKK militants targeted a bus carrying police officers on the highway connecting Diyarbakir and Mardin Provinces.
The policemen, two of whom seriously injured, were taken to nearby hospitals.
On Friday, three Turkish police officers were killed and several others injured when PKK militants carried out an attack in Turkey’s troubled eastern province of Tunceli.
The assault came after the militants detonated an improvised explosive device on the side of a road linking the provincial capital city of Tunceli and Elazig as an armored personnel carrier was passing by.
The attack prompted a swift response from the Turkish army, with reinforcements and attack helicopters dispatched to the area.
The military aircraft dropped bombs on the militants’ escape routes in the region, and ground forces launched a widespread search operation to arrest the assailants.
Turkey's largely Kurdish southeast has been hit by waves of violence in clashes between government forces and PKK militants after a ceasefire fell apart in July 2015.
The Turkish military has been conducting offensives against the positions of the group in northern Iraq and Syria as well.
The operations began in the wake of a deadly July 2015 bombing in the southern Turkish town of Suruc. More than 30 people died in the attack, which the Turkish government blamed on the Daesh Takfiri terrorist group.
After the bombing, the PKK militants engaged in a series of attacks against Turkish police and security forces, prompting the Turkish military operations.