Turkish riot police fired tear gas to disperse Kurdish protesters demonstrating against government plans to build a wall along part of the border with Syria.
Thousands of mostly young men, many waving red, yellow and green Kurdish flags, had earlier gathered to protest the plans
in the Turkish town of Nusaybin, separated from the Syrian town of Qamishli by a strip of no-man's land and barbed-wire fencing.
Turkey has begun building a 2m high wall along its border with Syria in an attempt to stop people from illegally crossing and smuggling problems.
Kurdish groups have decried the move as a government effort to prevent Kurdish communities on both sides of the Turkish-Syrian border from strengthening ties.
Syrian Kurdish groups say they have captured more territory from rebels in northeastern Syria in recent weeks,
tightening their control on an area where they have been seeking to establish autonomous rule.
Their assertiveness has posed a quandary for Ankara as it tries to make peace on its own soil with militants from the
Kurdistan Workers Party (PKK), which has fought for greater Kurdish autonomy in Turkey for three decades.