A group of Chinese warships led by the country's sole aircraft carrier entered the top half of the South China Sea on Monday after passing south of Taiwan, the self-ruled island's Defence Ministry said of what China has termed a routine exercise.
The move comes amid renewed tension over Taiwan, which Beijing claims as its own, ineligible for state-to-state relations, following U.S. President-elect Donald Trump's telephone call with the island's president that upset Beijing.
The Soviet-built Liaoning aircraft carrier has taken part in previous exercises, including some in the South China Sea, but China is years away from perfecting carrier operations similar to those the United States has practised for decades.
Taiwan's Defence Ministry said the carrier, accompanied by five vessels, passed southeast of the Pratas Islands, which are controlled by Taiwan, heading southwest.
The carrier group earlier passed 90 nautical miles south of Taiwan's southernmost point via the Bashi Channel, between Taiwan and the Philippines.
"Staying vigilant and flexible has always been the normal method of maintaining airspace security," said ministry spokesman Chen Chung-chi, declining to say whether Taiwan fighter jets were scrambled or if submarines had been deployed.
Chen said the ministry was continuing to "monitor and grasp the situation."