China on Monday sent 52 PLA Air Force aircraft towards Taiwan in the latest show of aerial force, marking a third record aerial intrusion in the past four days.

Taiwan’s Ministry of Defence said the aircraft included 34 J-16s and 12 nuclear capable H-6 bombers, and said it had responded by issuing radio warnings and deploying air defence systems to monitor the activity.

Monday’s entry of the PLA aircraft into the Air Defence Identification Zone followed a record 38 aircraft sent on Friday, when China marked its National Day, and 39 aircraft on Saturday in two separate waves.

Taiwan officials have hit out at the aerial intrusions into the ADIZ as acts of “military aggression” and “damaging regional peace”.

The intrusions have coincided with China’s National Day, marked on October 1, and come ahead of Taiwan’s National Day on October 10.

The aerial deployments were seen in Taiwan as “a demonstration to Taiwan and United States of the PLA’s joint combat capabilities and its ability to quickly assemble assets from different units”, the official CNA news agency reported from Taipei on Sunday.

Beijing has in the past timed intrusions into the ADIZ as a form of signalling. Prior to the National Day intrusions, another on September 23 coincided with Taiwan saying it had submitted an application to join the 11-nation CPTPP (Comprehensive and Progressive Agreement for Trans-Pacific Partnership) trade deal, days after China said it had formally applied to join the Pacific pact.

Last month, Beijing strongly hit out at Taiwan’s application to join the CPTPP. “There is only one China in the world,” spokesperson Zhao Lijian said, “and Taiwan is an inalienable part of China’s territory.”

Commenting on Saturday’s record air intrusions, U.S. State Department spokesperson Ned Price said the U.S. “is very concerned by the People’s Republic of China’s provocative military activity near Taiwan, which is destabilising, risks miscalculations, and undermines regional peace and stability.”