TAIPEI (Taiwan News) — Taiwan's Ministry of National Defense (MND) tracked eight Chinese naval vessels and four military aircraft around the country, including one warplane that entered the air defense identification zone (ADIZ) from Thursday to Friday (April 13-14).

From 6 p.m. Thursday to 6 a.m. Friday, the MND said that eight People's Liberation Army Navy (PLAN) vessels and four People's Liberation Army Air Force (PLAAF) military aircraft had been tracked around Taiwan. Of the aircraft, one had penetrated the southwest corner of the ADIZ.

The aircraft detected in the ADIZ was a Shaanxi Y-8 anti-submarine warfare aircraft. It flew in an area between the southwest edge of the median line and to the northeast of the Dongsha Islands.

The MND said that it responded by scrambling combat patrol aircraft, dispatching naval vessels, and deploying air defense missile systems.

On Monday (April 10), China completed three days of military exercises around Taiwan dubbed "Joint Sword," which included the deployment of 232 military aircraft and 32 naval vessels in and around Taiwan's air defense identification zone (ADIZ) simulating strikes on the country, while also conducting live-fire drills in the Taiwan Strait. China will reportedly launch a Long March 4B over a no-fly zone north of Taiwan on April 16.

According to the Center for Strategic and International Studies, gray zone tactics are “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.”