A Kurdish organization has accused the Turkish government of backing Islamic State militants fighting with Kurds in Syria, and suggested that could jeopardize a truce that Kurdish rebels in Turkey began in March 2013.

The statement was issued Wednesday by the Kurdish Communities Union, whose honorary leader is Abdullah Ocalan, the imprisoned leader of the Kurdistan Workers' Party, the Kurdish rebel group that has long fought Turkey for autonomy.

The umbrella group accused Turkey of "waging a war against the Kurdish people" and vowed to step up its "struggle."

It accused Turkey of supporting Islamic State group battling Syrian Kurdish forces along the Syria-Turkish border, and of stalling the peace process that it launched two years ago with the Kurdistan Workers' Party that led to the cease-fire in Turkey.