Taiwan has reported 38 Chinese military jets flying into its air defence zone on Friday – the largest incursion by Beijing to date.
The defence ministry said the planes, including nuclear-capable bombers, entered the area in two waves.
Taiwan responded by scrambling its jets and deploying missile systems.
China sees democratic Taiwan as a breakaway province, but Taiwan sees itself as a sovereign state.
Taiwan has been complaining for more than a year about repeated missions by China’s air force near the island.
“China has been wantonly engaged in military aggression, damaging regional peace,” Taiwan Premier Su Tseng-chang told reporters on Saturday.
The government in Beijing – which is marking 72 years since the founding of the People’s Republic of China – has so far made no public comment.
But it has previously said such flights were to protect its sovereignty and also targeted “collusion” between Taiwan and the US.
In a statement, Taiwan’s defence ministry said 25 People’s Liberation Army (PLA) planes entered the south-western part of the air defence identification zone (ADIZ) during daylight hours, flying near the Pratas Islands atoll.
An air defence identification zone is an area outside of a country’s territory and national airspace – but where foreign aircraft are still identified, monitored, and controlled in the interest of national security.
It is self-declared and technically remains international airspace.
This was followed by a second wave of 13 Chinese aircraft in the same area on Friday evening. They flew over waters between Taiwan and the Philippines.
The ministry said the Chinese aircraft included four H-6 bombers, which can carry nuclear weapons, as well as an anti-submarine aircraft.
Beijing often launches such missions to express displeasure at comments made by Taiwan.
It is not clear what prompted the latest mission.