|A Turkish army armoured vehicle is pictured in Karkamis on the Turkish-Syrian border in the southeastern Gaziantep province, Turkey.
A column of at least nine Turkish tanks crossed into Syria with the group of largely Arab and Turkmen rebels to drive Islamic State out of Jarablus and surrounding villages. A Reuters reporter at the border witnessed intense bombardments, with palls of black smoke rising around the town.
President Tayyip Erdogan said the operation was targeting both Islamic State and the Kurdish YPG militia, whose gains in northern Syria have alarmed Turkey. Ankara views the YPG as an extension of Kurdish militants fighting an insurgency on its own soil, putting it at odds with Washington, which sees the group as an ally in the fight against Islamic State.
"Whether it's Daesh (Islamic State) or the YPG, they are all terrorist organizations," Erdogan told a joint briefing in Ankara after meeting U.S. Vice President Joe Biden.
"A terrorist organization fighting another terrorist organization doesn't make it innocent," he said, adding that Islamic State had been forced out of Jarablus and that the town was now under control of the Syrian rebels.
Biden, who flew into Turkey, a key NATO ally with the alliance's second biggest armed forces, on a pre-planned trip hours after the operation began, tried to soothe Turkish concerns about Kurdish territorial gains in Syria.
"No (Kurdish) corridor. Period. No separate entity on the Turkish border. A united Syria," he told an earlier news conference with Turkish Prime Minister Binali Yildirim.
Biden said Washington had made clear to Kurdish militia fighters that they should return east of the Euphrates river again - a red line for Turkey - after helping to capture the city of Manbij south of Jarablus from Islamic State this month.
"They cannot, will not, and under no circumstances get American support if they do not keep that commitment," he said.