One lieutenant was killed and a major was severely injured in clashes between the Turkish Armed Forces (TSK) and the PKK-linked People's Protection Units (YPG) in Syria's Tel Rifaat Saturday.

In a statement, the Ministry of Defense said one of their comrades was "martyred" and another was critically wounded after YPG terrorists opened fire on Turkish forces in the Operation Olive Branch zone.

Artillery units are currently retaliating to the fire on the Turkish-Syrian border, it added.

In a later statement, the ministry said three Turkish soldiers near the border in southeastern Hakkari province were also killed after YPG terrorists launched mortar attacks from northern Iraq. A wide-scale air-supported counter-terrorism operation has been launched in the region in retaliation and jets are striking YPG targets, the ministry said.

The YPG, PKK's Syrian branch, has managed to occupy one-third of Syria under the guise of fighting against Daesh with U.S. support.

For the last three years, Tel Rifaat has been occupied by the YPG, which has dubbed the territory between Tel Rifaat and Manbij as the "Shahba Canton."

The YPG occupied Tel Rifaat in 2016 in hopes of linking Afrin, a city in northwestern Syria, to areas under its control east of the Euphrates River, thus establishing a zone of influence along Syria's border with Turkey.

Syria's Al-Bab district, however, which is located between Tel Rifaat and Manbij, falls within Operation Euphrates Shield's area-of-operations, thus disrupting the YPG's sought-for territorial link.

Later in January 2018, the Turkish military and Free Syrian Army (FSA) elements launched Operation Olive Branch to clear Afrin district from terrorist groups, liberating the town center in March.

Some 250,000 refugees from Tel Rifaat and its outskirts have taken up temporary residence in the opposition-held city of Azaz, located adjacent to the Euphrates Shield zone.