The Ministry of National Defense (MND) of Taiwan tracked seven Chinese military aircraft and three naval vessels around the island between 6 a.m. (GMT+8) on Monday (Jan. 22) and 6 a.m. on Tuesday (Jan. 23), Report informs via Taiwan News.

Of the seven People’s Liberation Army (PLA) aircraft, one jet fighter crossed the Taiwan Strait median line in the northeast sector of the island’s air defense identification zone (ADIZ), according to the MND. In response, Taiwan sent aircraft and naval ships and deployed air defense missile systems to monitor the PLA activity.

In addition, one Chinese balloon was detected crossing the median line at 10:43 p.m. on Monday 163 km (88 NM) west of Keelung. It was traveling northeast and disappeared at 11:10 p.m.