AFP journalists said the hundreds of young demonstrators fought back by hurling rocks and setting up barricades on the road leading to a nearby border crossing.

"We've come to support our brothers in Syria under attack by Daesh," Turkish Kurdish demonstrator Mehmet Eminakma told AFP, referring to the Islamic State (IS) jihadist group.

He also charged that Turkish authorities were blocking young Syrian Kurds who had accompanied their families to safety inside Turkey from returning to the battlefront.

The security forces forced demonstrators away from a barbed wire border fence that stands just five kilometres (three miles) from the town of Ain al-Arab, where Kurdish fighters are holding off the jihadists.

As many as 70,000 Syrian Kurds have poured into Turkey since Friday fleeing the IS offensive in northeastern Syria, according to the UN's refugee agency, UNHCR.