TAIPEI (Taiwan News) — The Ministry of National Defense tracked 28 Chinese military craft and eight naval ships between 6 a.m. on Saturday and the same time Sunday.

The ministry reported that 18 out of the 20 sorties crossed the median line and entered Taiwan’s northern, central, and southwestern air defense identification zone, or ADIZ. In response, Taiwan deployed aircraft, naval ships, and coastal-based missile systems to monitor Chinese activity.

So far this month, the defense ministry has tracked Chinese military aircraft 187 times and ships 207 times. Since September 2020, China has increased its use of gray zone tactics by incrementally increasing the number of military aircraft and naval vessels operating around Taiwan.

Gray zone tactics are defined as “an effort or series of efforts beyond steady-state deterrence and assurance that attempts to achieve one’s security objectives without resort to direct and sizable use of force.”