Chinese fighter jets harassed a Dutch warship conducting patrols to enforce U.N. sanctions on North Korea, according to the Netherlands’ defense ministry.

“In the East China Sea, two Chinese fighter jets circled the naval ship HNLMS Tromp several times. Additionally, the ship’s NH90 maritime combat helicopter was approached by two Chinese fighter jets and a Chinese helicopter during a patrol,” the Dutch ministry stated in a press release on Friday.

The Chinese approach created a “potentially unsafe situation,” the ministry said, adding that the incident “took place in international airspace.”

China’s Ministry of National Defense on Tuesday disputed the Dutch