They said work had begun Saturday on "the first practical steps -- in the Ras al-Ain area -- in removing some earth mounds and withdrawing a group of (Kurdish) People's Protection Units and heavy weapons".

The so-called "safe zone" agreed by Washington and Ankara earlier this month aims to create a buffer between the Turkish border and Syrian areas controlled by the Kurdish People's Protection Units (YPG), a group Ankara sees as "terrorists".