TAIPEI (Taiwan News) — The Ministry of National Defense said it had spotted nine aircraft and two ships from China’s military in areas surrounding Taiwan by 5 p.m. Saturday (Nov. 5).

Only one plane, a Xi’an H-6 bomber, entered the southwest sector of the country’s air defense identification zone (ADIZ), the military tweeted. The aircraft was spotted close to the Taiwan-held island of Dongsha, one of many disputed islands in the South China Sea.

The appearance of Chinese military planes in the area have often been interpreted as a rehearsal for a blockade of air traffic between Taiwan’s main island and Dongsha, which is the site of a military airport.

Responding to the intrusion into the ADIZ, Taiwan’s military on Saturday tasked aircraft in Combat Air Patrols (CAP) and naval vessels, deployed land-based air defense missile systems to monitor the Chinese activities, and issued radio warnings.