Taiwan's defence ministry said on Friday it had detected a renewed incursion by Chinese military aircraft across the sensitive Taiwan Strait, as China reported its navy had carried out combat drills with landing craft.
Over the past four years, China's military has significantly ramped up its activities around democratically-governed Taiwan. Beijing views the island as its own territory, a position the government in Taipei strongly rejects.
The defence ministry, in its daily morning update on Chinese activities in the previous 24 hours, said 14 Chinese military aircraft crossed the Taiwan Strait's median line, getting as close as 41 nautical miles (76 km) to the northern Taiwanese port city of Keelung, home to a major navy base.
The median line is used to serve as an unofficial border between the two sides, but Chinese military aircraft now regularly cross it. China says it does not recognise the line's existence.
Taiwan said on Thursday that China had carried out a "joint combat readiness patrol" near the island for the second time in a week.
China's defence ministry did not answer calls seeking comment on Friday, the country being in the middle of its Labour Day holiday.
On Thursday, the Eastern Theatre Command of China's People's Liberation Army, which is responsible for the area around Taiwan, showed pictures on its WeChat social media account of ships carrying out what it called live combat landing drills.
It did not say when or where exactly the exercises took place, but showed images of ship-mounted guns opening fire and operating in formation.
"The vanguard of the landing team are always ready to fight," it said in text to accompany the pictures.
The island's top security official said on Wednesday that Taiwan is on alert for China to carry out military exercises following the inauguration of President-elect Lai Ching-te later this month.
Taiwan National Security Bureau Director-General Tsai Ming-yen said China had begun using unusual new tactics, including staging night time combat patrols and using landing ships and minesweepers in those patrols.
Lai, who is inaugurated on May 20 after winning election in January, is strongly disliked by China which believes him to be a dangerous separatist. China's government has rejected his repeated offers of talks, including one made last week.
Lai, like current President Tsai Ing-wen, rejects Beijing's sovereignty claims; both say only the island's people can decide their future.
Lai has been Taiwan's vice president for the past four years.
