TAIPEI (Taiwan News) — Military watchers intercepted pilot radio communications Monday showing Chinese military aircraft issuing radio demands to Taiwan’s Air Force, while nearby US military aircraft broadcast responses in Taiwan’s southwestern air defense identification zone (ADIZ).

People’s Liberation Army Navy Air Force pilots issued consecutive radio demands to Taiwanese aircraft at 8:57 a.m., 8:59 a.m., and 9 a.m., claiming they were endangering flight safety and demanding that they maintain a safe distance, Liberty Times reported.

Nearby US military aircraft broadcast messages as many as nine times in response, asserting their lawful right to operate in international airspace. One US military aircraft reiterated that its operations had taken into consideration the rights of all countries, rejecting the Chinese military demands.

Taiwan’s defense ministry tracked seven Chinese military aircraft, five naval vessels, and one official ship around Taiwan between 6 a.m. Sunday and 6 a.m. Monday.

The seven PLA aircraft crossed the Taiwan Strait median line in Taiwan’s northern and southwestern ADIZ, according to the Ministry of National Defense. In response, Taiwan deployed aircraft, naval ships, and coastal-based missile systems to monitor PLA activity.

So far this month, the ministry has tracked Chinese military aircraft 120 times and ships 132 times.