Turkish and Russian troops in armored vehicles on Tuesday began their second joint ground patrol in northern Syria near the town of Kobani, under a deal that has forced a Kurdish militia away from Turkey's border. Nearly a month ago, Turkey and Syrian rebel allies launched a cross-border incursion against Kurdish YPG fighters, seizing control of 120 km (75 miles) of land along the frontier. Under a subsequent deal, Russia and Turkey agreed to push the YPG militia to a depth of at least 30 km (19 miles) south of the border and to hold joint patrols to monitor the agreement. President Tayyip Erdogan said on Tuesday that the YPG had not withdrawn from that planned "safe zone", despite Turkey's agreements with both Russia and the United States. Tuesday's patrol was launched some seven km east of Kobani, a Syrian border town of special significance to the YPG, which fought off Islamic State militants trying to seize it in 2014-15 in one of the fiercest battles of the Syrian war. Armored vehicles crossed through a gap in the border wall to the Syrian side and headed east, a witness said. Security sources said the patrol would cover a distance of 72 km at a depth of five km from the border. The Turkish Defense Ministry shared photos on Twitter showing Turkish and Russian soldiers meeting at the border and studying maps before the start of the patrol. It said drones were also taking part. Russia is the Syrian government's most powerful ally and since 2015 has helped it retake much of the country from rebels, turning the tide in the civil war. The Turkish-Russian deal enabled Syrian government forces to move back into border regions from which they had been absent for years. Russian military police arrived in Kobani on Oct. 23 under the deal reached by Erdogan and Russian president Vladimir Putin. The first patrol, on Friday, was held around the Syrian border town of Darbasiya, east of the region from where Turkish and their Syrian rebel allies forced out the YPG fighters. Erdogan said last week that Turkey planned to establish a "refugee town or towns" in that region between Tel Abyad and Ras Al-Ain, part of a project which state media have said would cost 151 billion lira ($26 billion). Ankara launched its offensive against the YPG following President Donald Trump's abrupt withdrawal of 1,000 US troops from northern Syria in early October. The YPG helped the United States smash the Islamic State caliphate in Syria. — Reuters