Taiwan has said a large incursion of Chinese military jets flew into its air defence zone on Sunday.
The defence ministry said 19 aircraft including fighters and nuclear-capable bombers entered its so-called air defence identification zone (ADIZ).
Taipei has been complaining for more than a year about repeated missions by China's air force near the island.
China sees democratic Taiwan as a breakaway province, but Taiwan sees itself as a sovereign state.
Taiwan's defence ministry said Sunday's mission by the Chinese air force involved four H-6 bombers, which can carry nuclear weapons, as well as an anti-submarine aircraft.
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.
The defence ministry released a map showing a flight path north-east of the Pratas, closer to the Chinese coast than the Taiwanese coast.
Missile systems were deployed and combat aircraft dispatched to warn away the Chinese planes, the ministry added.
China has not yet officially commented.
Beijing often launches such missions to express displeasure at comments made by Taiwan.
In June, it sent 28 military jets into the ADIZ - the largest incursion reported by Taiwan to date.
On 24 January, a similar mission saw 15 aircraft entering Taiwan's air defence zone while on 12 April, Taiwan reported 25 jets.
It is not clear what prompted the latest mission.
However, last week Taiwan's defence ministry warned that China's armed forces could "paralyse" Taiwan's defences and that the Chinese threat is growing.
China and Taiwan: The basics
- Why do China and Taiwan have poor relations? China and Taiwan were divided during a civil war in the 1940s, but Beijing insists the island will be reclaimed at some point, by force if necessary
- How is Taiwan governed? The island has its own constitution, democratically elected leaders, and about 300,000 active troops in its armed forces
- Who recognises Taiwan? Only a few countries recognise Taiwan. Most recognise the Chinese government in Beijing instead. The US has no official ties with Taiwan but does have a law which requires it to provide the island with the means to defend itself.