China’s People’s Liberation Army (PLA) launched three-day-long military exercises in the airspace and waters surrounding Taiwan on Thursday, disrupting and canceling flights throughout Asia and threatening to cause further flight cancellations in the coming days, the Korea JoongAng Daily reported, noting that Beijing ordered the PLA drills in response to U.S. House Speaker Nancy Pelosi’s visit to Taipei this week.

“[D]isruptions in operations of Korean airlines began with Asiana Airlines announcing Thursday that direct flight schedules to Taiwan will be adjusted starting the same day,” the newspaper reported on August 4.

Asiana Airlines announced that its direct flights from Incheon, South Korea, to Taiwan Taoyuan International Airport would depart three hours earlier than originally scheduled on August 4.

“Korean Air, Asiana Airlines and low-cost carriers (LCCs) have also decided to change routes for some Southeast Asian flights. Flight times could be extended by a minimum of 15 minutes to a maximum of one hour and 30 minutes,” the Korea JoongAng Daily relayed.

“Passengers will have no choice but to experience inconveniences due to these flight schedule changes and delays,” an unidentified South Korean LCC official told the newspaper. “Additional costs are also incurred for airlines. We hope the situation gets back to normal soon.”

“Authorities have canceled at least 40 flights at Taiwan Taoyuan International Airport (TPE) in Taoyuan as of Aug. 4,” the Canadian private security firm GardaWorld’s Crisis24 information service reported.

Crisis24 noted that China’s PLA “has banned civilian aircraft and vessels from entering the areas for the exercises’ duration.”

“The drills and associated exclusion zones may prompt regional maritime shipping delays. The exercises could restrict shipping traffic in waterways to ports in Taiwan. Flight disruptions cannot be ruled out at airports in Taiwan and, potentially, offshore helicopter services,” the information service cautioned.

China’s PLA launched live-fire military drills in the waters and airspace directly surrounding Taiwan, a sovereign island nation located off China’s southeastern coast, on August 4. The exercises are slated to last through August 7.

“China’s military confirmed multiple firings of conventional missiles in waters off Taiwan as part of planned exercises in six zones set to run until noon on Sunday [August 7]. It activated more than 100 planes, including fighter jets and bombers, and over 10 warships,” Reuters relayed on Thursday citing the state-run China Central Television (CCTV).

“Taiwan said 11 Chinese Dongfeng ballistic missiles had been fired in nearby waters — the first time since 1996,” Reuters observed.

China had already begun harassing Taiwan on August 3, one day before its live-fire drills launched, by penetrating Taiwan’s sensitive air defense identification zone (ADIZ). Taiwan’s Ministry of Defense said it scrambled fighter jets to warn off 22 Chinese military aircraft that crossed the Taiwan Strait median line — a barrier separating Taiwan from China — into Taiwan’s ADIZ that day. The defense ministry said it further ordered Taiwanese troops to fire flares late on Wednesday night local time after spotting four Chinese military drones flying in the airspace directly above Taiwan’s Kinmen Islands.

U.S. House Speaker Nancy Pelosi became the highest-ranking U.S. government official to visit Taiwan in 25 years on August 2 when she landed in Taipei. She met with Taiwanese government officials, including President Tsai Ing-wen, through August 3. Pelosi’s symbolic visit to Taiwan seriously upset Beijing, which considers Taiwan to be a part of China that should be “reunified” with the country.