TAIPEI (Taiwan News) — As voters in Taiwan prepared to go to the polls Saturday (Nov. 26) to select new city and county leaders, the Ministry of National Defense said it had spotted 11 aircraft and four ships from China’s military in areas surrounding the country by 6 a.m. Saturday (Nov. 26).

Of the 11 aircraft tracked during the 24-hour period leading up to 6 a.m. on Saturday, one unmanned combat aerial vehicle (UCAV) and four bombers entered the southwest sector of the country’s air defense identification zone (ADIZ), the military tweeted. The drone was a CASC CH-4 Rainbow reconnaissance UCAV while the bombers were Xi’an H-6 twin-engine jets.

The latter were 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 has 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 intrusions into the ADIZ, Taiwan’s military tasked aircraft in Combat Air Patrols (CAP) and naval vessels, and deployed land-based air defense missile systems to monitor Chinese activities.