Free Syrian Army troops also entered PYD/PKK occupied areas in northern Syria.
Turkish jets on Saturday destroyed observation posts and many other targets of PYD/PKK terrorists in Afrin region, northern Syria, as part of "Operation Olive Branch".
"108 targets, which were used as shelters, hideouts and ammunition depots by terrorist organizations PKK/KCK/PYD-YPG and Daesh in seven areas, were destroyed by air forces," said Turkish General Staff in a fresh statement.
The army said the operation continued as planned and it aims to establish security and stability along Turkish borders and the region as well as to eliminate terrorists and to protect Syrian people from the terrorists’ oppression and cruelty.
“72 planes which took part in the operation have safely returned to their bases to get ready for the next missions,” read the statement.
Earlier, airstrikes were reported after Turkish jets had been heard flying in southern Hatay province's Reyhanli and Kirikhan districts near the Syrian border.
Following Turkish Armed Forces’ artillery shootings targeting terror zones, Free Syrian Army (FSA) members have also entered Afrin via armored vehicles from Kilis-Hatay border zone.
The army first announced that it launched “Operation Olive Branch” on Saturday at 5.00 p.m. (1400GMT).
The operation is carried out under the framework of Turkey’s rights based on international law, UN Security Council’s decisions and self-defense right under UN charter, said the military.
Turkish fighter jets also hit Minnigh military airbase occupied by terrorist group PYD/PKK in Afrin region.
Speaking about the operation in western Usak province, President Recep Tayyip Erdogan said his country is “doing what is necessary.”
In his Twitter post, Turkish Deputy Prime Minister Bekir Bozdag asserted the operation just targeted "the terrorist groups and the terrorists as well as their barracks, shelters, positions, weapons, vehicles, and equipment.
"Civilians are never a target. Every kind of planning has been done to avoid any damage to civilians,” said.
Ahead of the “Operation Olive Branch”, Turkish Chief of General Staff Gen. Hulusi Akar spoke to his Russian counterpart Joseph Dunford and Russian Gen. Valery Gerasimov separately over phone.
Turkish Chief of General Staff Gen. Hulusi Akar (L) conducts the 'Operation Olive Branch' to Afrin, as Commander of the Turkish Air Forces Hasan Kucukakyuz (right 2) and Deputy Chief of the Turkish General Staff Umit Dundar (R) sit next to him at the operations center in the Turkish General Staff Headquarters in Ankara
Also, Turkish foreign ministry summoned and informed the U.S., Russian and Iranian mission heads in Ankara about Afrin-related latest developments.
The PYD/PKK is the Syrian offshoot of the PKK terrorist group, which has been designated a terrorist organization by Turkey, the U.S. and the EU.
Since the mid-1980s, the PKK has waged a wide-ranging terror campaign against the Turkish state in which an estimated 40,000 people have been killed.
More than 1,200 security personnel have been martyred since July 2015 when the group resumed its armed campaign against the Turkish state following a fragile cease-fire.