MURSITPINAR, Turkey - The siege by Islamic State militants of a largely Kurdish Syrian border town has become a rallying point for Turkey's Kurds, not just against the Sunni insurgents but against the Turkish state, endangering a fragile peace process with Ankara.
Fuelled by suspicions that Turkey is supporting the Sunni Muslim militants, the Kurds have clashed at Mursitpinar in Turkey with security forces who have fired water cannon and tear gas partly in a bid to prevent them joining the fight across the border in the Syrian town of Kobani.
The growing Kurdish anger towards Ankara poses the biggest threat so far to a historic peace process initiated in 2012 by now President Tayyip Erdogan, an effort to end a three-decade insurgency by militants pushing for greater Kurdish rights.
The conflict has killed 40,000 people, most of them Kurds.
The outlawed Kurdistan Workers Party (PKK) said Ankara had violated a ceasefire, declared by its jailed leader Abdullah Ocalan in March last year, by supporting Islamic State.
Commander Murat Karayilan declared the ceasefire "finished"in an interview with a TV station close to the PKK this week.
While Kurdish politicians involved in the process have been more cautious, the allegations of Turkish support for Islamic State - strongly denied by Ankara - are widely believed by Kurds on both sides of the border.
"Turkey won't allow us to defend Kobani because they support ISIL," said balaclava-clad Shirwan, 28, holding aloft the red-starred PKK flag as a crowd gathered to protest near the Mursitpinar border gate. "Where is the peace process?"
Deputy Prime Minister Yalcin Akdogan slammed the "ingratitude" of protesters, noting that Turkey had taken in some 150,000 Syrian Kurds fleeing the Islamic State onslaught in a matter of just days.
"You have opened your gates, your heart, but on the other side some are constantly fuelling tensions. These are not good things for the peace process, they don't fit with the spirit of the process," Akdogan said as the protests spread this week.
Another two ministers affirmed the government's commitment to the peace process on Friday and said it would not be sidelined by "provocations".
"We have our own road map. We are leading the solution process, it's not being shaped by others who want to lead us," Interior Minister Efkan Ala told reporters.
Kurdish suspicions about Ankara's relationship with Islamic State deepened after 46 Turkish hostages held for more than three months by the group were released on Saturday, with no shots fired and no ransom paid.