Turkish Defense Minister Nurettin Canikli announced on Friday that the military operation in the Kurdish-held region of Afrin in northern Syria has gotten underway. The cross-border bombardment took place after days of threats from Turkish President Recep Tayyip Erdogan to crush the Syrian Kurdish People’s Protection Units (YPG) in Afrin in response to growing Kurdish strength across a wide stretch of north Syria. “The operation has actually de facto started with cross-border shelling,” confirmed Canikli, adding that no troops had crossed into Afrin. Reuters TV filmed Turkish artillery at the border village of Sugedigi firing on Friday morning into Afrin region, and the YPG said Turkish forces fired 70 shells at Kurdish villages between midnight and Friday morning. Shelling continued in the late afternoon, said Rojhat Roj, a YPG spokesman in Afrin. Roj said it was the heaviest Turkish bombardment since Ankara stepped up threats to take military action against the Kurdish region. He said that the YPG will retaliate with force against any attack against Afrin. Canikli said Ankara was determined to destroy the Kurdish group. “All terror networks and elements in northern Syria will be eliminated. There is no other way,” he said. Turkey has been angered by US military support for the Kurdish YPG-dominated Syrian Democratic Forces which spearheaded the fight against ISIS in Syria, and by an announcement that the United States would stay in Syria to train about 30,000 personnel in the swathe of eastern Syria under SDF control. Turkey says the YPG is a terrorist group and a branch of the outlawed Kurdistan Workers Party which has waged an insurgency in southeast Turkey for decades, and Canikli criticized Washington for its continued emphasis on countering ISIS.