Protesters wait in front of a barricade during clashes with Turkish riot police in Istanbul's Gazi district, on July 26, 2015. Turkey has launched a two-pronged "anti-terror" cross-border offensive against Islamic State (IS) jihadists and Kurdistan Workers Party (PKK) militants after a wave of violence in the country, pounding their positions with air strikes and artillery. But the expansion of the campaign to include not just IS targets in Syria but PKK rebels in neighbouring northern Iraq -- themselves bitterly opposed to the jihadists -- has put in jeopardy a truce with the Kurdish militants that has largely held since 2013. AFP PHOTO / OZAN KOSE