NICE, July 15, 2016 (Xinhua) -- People gather to mourn victims of an attack in which a truck drove through crowds during Bastille Day celebrations in Nice, France on July 15, 2016. People in the wake of the deadly Nice attack on Thursday, French Prime Minister Manuel Valls on Friday morning declared three days of national morning, to begin on July 16. (Xinhua/Xu Jinquan)