The Turkish military began setting up observation posts in northern Syria’s Idlib province on Thursday as part of a ‘de-escalation’ deal which it agreed on last month with Iran and Russia. Ankara said on Friday the Turkish forces in the region were carrying out their duties in line with rules of engagement agreed on with Moscow and Tehran. The deployment is also intended to rein in the Kurdish YPG militia, which holds the adjacent Afrin region, Reuters quoted a senior rebel official involved in the operation as saying. Turkey sent a convoy of about 30 military vehicles into rebel-held northwest Syria through the Bab al-Hawa crossing in Idlib, according to sources.