Within a radius of nearly one km 2, the roads of Hai Ba Trung - Nguyen Dinh Chieu - Nam Ky Khoi Nghia - Nguyen Du - Pham Ngoc Thach and Le Duan (District 1 and 3) are all sealed off. Security forces sprayed water cannons dispersed the crowd. The sound of explosions, gunfire, tear gas ... made the air urgent.