Taiwan remained on high alert on Wednesday after China staged massive military drills around the island the previous day, keeping its emergency maritime response centre running as it monitored Chinese naval manoeuvres, the coast guard said.

The exercises named “Justice Mission 2025” saw China fire dozens of rockets towards Taiwan and deploy a large number of warships and aircraft near the island, in a show of force that drew concern from Western allies.

Taipei condemned the drills as a threat to regional security and a blatant provocation.

Chinese ships were moving away from Taiwan, but Beijing had yet to formally declare the end of the exercises, according to Kuan Bi-ling, head of Taiwan’s Ocean Affairs Council.

“The maritime situation has calmed down, with ships and vessels gradually departing. As China has not announced the conclusion of the military exercises, the emergency response centre remains operational,” she said in a post on Facebook late on Tuesday.

A Taiwan coast guard official told Reuters all 11 Chinese coast guard ships had left waters near Taiwan and were continuing to move away. A Taiwan security official said emergency response centres for the military and coast guard stayed active.

Currently there are more than 90 Chinese naval and coast guard vessels in the region, with many of them being deployed in the South China Sea, near Taiwan and the East China Sea in a large maritime show of force, two security officials in the region told Reuters.

The officials, who declined to be identified due to the sensitivity of the matter, said the size of China’s maritime deployment has steadily increased since early this week.

China is in the middle of what is traditionally a busy season for military exercises.

Taiwan’s defence ministry on Wednesday said 77 Chinese military aircraft and 25 navy and coast guard vessels had been operating around the island in the past 24 hours.

Among them, 35 military planes had crossed the Taiwan Strait median line that separates the two sides, it added.

“STERN WARNING”

As the war games unfolded, the ambassadors to China from countries that make up the Quad grouping, formed to conduct security dialogue, convened in Beijing on Tuesday.

United States Ambassador David Perdue posted on X a photo of himself with the Australian, Japanese and Indian ambassadors at the US embassy. He called the Quad a “force for good” working to maintain a free and open Indo-Pacific but gave no details about the meeting.

The US embassy did not immediately respond to a request for comment about the meeting.

The drills, China’s most extensive war games by coverage area to date, forced Taiwan to cancel dozens of domestic flights and dispatch jets and warships to monitor. Soldiers were seen running rapid-response drills including putting up barricades at various locations.

China regarded the exercises as a “necessary and just measure” to safeguard national sovereignty and territorial integrity, its Taiwan Affairs Office spokesperson Zhang Han told reporters on Wednesday at weekly briefing. They were “a stern warning against Taiwan independence separatist forces and external interference”, she added.

China’s state news agency Xinhua published an article summarising “three key takeaways” from the drills, which began 11 days after the United States announced a record $11.1 billion arms package for Taiwan.

The simulated “encirclement” demonstrated the People’s Liberation Army’s ability to “press and contain separatist forces while denying access to external interference – an approach summarised as ‘sealing internally and blocking externally’,” the article said, citing Zhang Chi, a professor at the PLA National Defence University.

While China’s war games grow increasingly realistic and bold, it was unlikely to start a war at the cost of its reputation, said Lyle Goldstein, the Asia programme head of US think tank Defense Priorities.

“They threaten and bluster a lot, but ultimately (a war) would be very costly for China no matter what,” Goldstein said.

China claims democratically governed Taiwan as its own territory and has not ruled out using force to take it under Chinese control. Taiwan rejects China’s claims.