On an army base in the island’s southern county of Pingtung on Tuesday, Taiwanese forces fired howitzer shells into the sea as part of an exercise to simulate a hostile amphibious assault. A second day of anti-landing drills was scheduled for August 11.

The spotlight has been fixed on the Taiwan Strait over the last week after House Speaker Nancy Pelosi ignored Beijing’s warnings not to make a historic visit to Taipei between August 2 and 3, becoming the most senior American official to set foot on the island in a quarter-century.

China claims Taiwan as its own and vowed to respond militarily to the move, which it viewed as an elevation of the unofficial relationship between the United States and Taiwan. Beijing announced military exercises around the island between August 4 and 7, the largest since the Third Taiwan Strait Crisis of 1995 and 1996.

The Chinese war games, which involved the first-ever firing of ballistic missiles over Taiwan into waters east of the island, featured six closure zones that simulated a blockade of major Taiwanese ports. Initially scheduled to conclude over the weekend, the People’s Liberation Army continued the drills on Monday before announcing a second extension.

A statement by the PLA’s Eastern Theater Command—forces expected to spearhead any future invasion of the island—said combat exercises in the seas and skies around Taiwan would continue through August 9, with a focus on “joint containment” and “joint safeguarding” operations.

Between August 4 and 8, the PLA drills included themes such as “precision strike,” “area denial,““air superiority combat” and “anti-submarine warfare.” The Chinese military exercises have regularly featured dozens of warplanes and over a dozen warships, according to Taiwan’s defense ministry.

On Sunday, the Taiwanese defense ministry said at least 13 PLA warships and intelligence-gathering vessels were operating near the island’s contiguous zone—24 nautical miles from the coast—on a daily basis. Chinese aircraft and ships haven’t entered Taiwan’s territorial airspace or sea, the statement said.

Joseph Wu, Taiwan’s foreign minister, told reporters in Taipei on Tuesday that Beijing had used Speaker Pelosi’s visit as a pretext for its military exercises, which had “hindered the normal operations of one of the busiest air and shipping routes in the Indo-Pacific region.”

“China has openly declared its ownership over the Taiwan Strait,” Wu said. “On this occasion, China has also taken specific actions to break the long-standing tacit agreement on the median line of the Taiwan Strait. And after the drills conclude, China may try to routinize its action in an attempt to wreck the long-term status quo across the Taiwan Strait.”

The median line has acted as an unofficial buffer to prevent military clashes in the Taiwan Strait since the 1950s, especially during the Cold War, when Taiwanese and Chinese forces enjoyed some parity. Beijing, whose military now possesses an overwhelming numerical advantage over Taipei’s, began sending aircraft across the center of the strait in 2019.

Analysts believe China will take advantage of the growing power imbalance to further squeeze the seas and airspace around Taiwan, with Beijing’s latest drills suggesting an attempt to normalize PLA operations near the island in the future.

At a monthly press conference last month, Chinese defense ministry spokesperson Wu Qian already had articulated Beijing’s new position on the matter: “Taiwan is part of China. There is no so-called median line between both sides of the Taiwan Strait.”

Taiwan’s Wu called on the international community to push back against the Chinese military maneuvers with actions such as U.S-led freedom of navigation exercises and Taiwan Strait transits.

Last week, the White House said U.S. forces would continue routine air and maritime transits through the strait in the next few weeks.