China sent navy ships and a large group of warplanes, including fighter jets and bombers, toward Taiwan over two days, the self-ruled island’s defense ministry said on Wednesday.

The Chinese People’s Liberation Army sent 38 warplanes and 9 navy vessels around Taiwan, between 6 AM Tuesday to 6 AM Wednesday. From Wednesday morning until noon time, the military flew another 30 planes, among which included J-10 and J-16 fighters, AP has reported.

Many of these also crossed the midline of the Taiwan Strait, an unofficial boundary that had been considered a buffer between the island and mainland.

Taiwan is scheduled to hold the annual Han Guang exercise later this month, in which its military will hold combat readiness drills against preventing an invasion.

It will also conduct the annual Wan’an exercises aimed at preparing civilians for natural disasters and practicing evacuations in case of an air raid.