Hundreds of Kurds on Friday broke through the Turkish border into Syrian territory to join Kurdish forces battling the advance of Islamic State (IS) militants around the Syrian town of Ain al-Arab.
Turkish security forces have on previous occasions halted activists from moving into Syria to fight IS, sparking clashes with local Kurds on the border.
Turkey is hosting over 160,000 refugees who fled Ain al-Arab, known as Kobane to the Kurds, from the advance of IS jihadists who have carried out a wave of atrocities including beheadings.
But others are also now keen to move in the other direction to join the fight.
Turkish and Syrian Kurds on both sides worked to pull down the barbed wire and mesh border fences, as well as the concrete border posts around the border crossing of Mursitpinar, an AFP photographer said.
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The Kurds from the Turkish side of the border, including people who had originally fled from Ain al-Arab, moved onto the Syrian side, saying they wanted to fight IS and save their homes.
Once over the border, they were given an emotional welcome by fighters from the People's Protection Units (YPG), a Kurdish rebel group operating on Syrian territory, pro-Kurdish Firat news agency reported.
Turkish security forces did not impede the movement of Kurds over the border back to Syria on this occasion.
The movement came amid new reports on Kurdish news media that IS was renewing its assault around Ain al-Arab which is just a few kilometres south the Turkish border.
Kurdish rebels who have been fighting the Turkish authorities for self-rule in a bloody 30-year insurgency had warned about the future of Turkey's own peace process if Kurds were not allowed to cross the border into Syria.
Meanwhile, the Turkish army said a mortar shell fired from Syria during the clashes there landed on an empty field on the Turkish side of the border. It caused no damage nor casualties.