China sent dozens of warplanes, including fighter jets and bombers, toward Taiwan, the island’s Defence Ministry said on Saturday, marking a forceful display days before the democracy plans to hold military exercises aimed at defending itself against a possible invasion.

Taiwan is due to hold its annual Han Kuang exercise next week, during which its military will hold combat readiness drills for 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.

The Chinese People’s Liberation Army sent 37 aircraft and seven navy vessels around Taiwan between 6 am on Friday and 6 am on Saturday, the ministry said in a statement.

Among them were J-10 and J-16 fighters and H-6 bombers, and 22 of the detected warplanes crossed the midline of the Taiwan Strait — an unofficial boundary that had been considered a buffer between the island and mainland — or entered Taiwan’s air defence identification zone near its southern part, the statement said.

Taiwan and China split in 1949 following a civil war that ended with the ruling Communist Party in control of the mainland. The island has never been part of the People’s Republic of China, but Beijing says it must unite with the mainland.

In recent years, China has shown displeasure at political activities in Taiwan by stepping up the number of military planes sent toward the island.

China held huge military drills in response to former United States House Speaker Nancy Pelosi’s visit to Taiwan in August. It fired missiles over the island in a significant escalation that disrupted trade lanes in the Taiwan Strait and forced airplanes to reroute flights.

In April, the PLA also held large-scale combat readiness drills in the air and sea around the island in response to Taiwan’s President Tsai Ing-wen meeting with current US House Speaker Kevin McCarthy.