On June 7, the Dutch frigate HNLMS Tromp, set to join the exercise, was on patrol in the East China Sea. It was supporting UN sanctions against North Korea. Chinese jets harassed the ship, circling and closely following it. When a Dutch helicopter took off for a patrol, it was also approached by a Chinese jet and helicopter. Photos show these were a Z-19 attack helicopter and a JH-7 fighter-bomber.#chinaobserver