On a Sunday evening in early May, as a sandstorm whirled over the village of Bilge in Turkey’s mainly Kurdish south-east, a lively engagement party wound to a close. After a feast of steaming meat and rice, trays of sugary baklava and Turkish coffee, the several dozen guests retired to two rooms, men and women, to say a final prayer.

That was when five men, armed with machine guns and hand grenades, stormed the house and opened fire, killing 47 people, including six children as well as the bride and groom.