China has pressured Taiwan by increasing its military presence around the island, and Taipei is on high alert for further Chinese actions after President Xi Jinping discussed Taiwan with US President Donald Trump in Beijing this month.
China views democratically governed Taiwan as its own territory, and operates its warships and warplanes around the island on an almost daily basis. Taiwan's government rejects Beijing's sovereignty claims.
Late on Monday, Taiwan's defence ministry said it had detected 21 Chinese aircraft, including J-16 fighters and drones, operating all around the island, which, along with warships, were carrying out a "joint combat readiness patrol".
China's defence ministry did not immediately respond to a request for comment.
Taiwan's defence ministry published three pictures taken by its own forces - one from an F-16 jet of two Chinese fighters trailing a Y-20 aerial refuelling aircraft, one of the Chinese warship the Yinchuan, and one of a Taiwanese navy sailor watching the same ship through binoculars.
Speaking to reporters in Taipei on Tuesday, Pan Chun-kuang, from the ministry's intelligence department, said the Chinese "combat patrol" had already ended.
But Taiwan continues to track the movements of China's aircraft carrier, the Liaoning, operating in the Western Pacific, and will release more details of Chinese activities as needed, he added.
Writing on his X account about the patrol and presence of the Liaoning carrier group, Taiwan National Security Council Secretary-General Joseph Wu said what China was doing was "unprovoked".
"The PRC is the sole source of instability in the Indo-Pacific," he added, referring to the People's Republic of China.
China carried out a similar "readiness patrol" last Tuesday, the day before Taiwan President Lai Ching-te marked his second year in office. China calls Lai a "separatist" and has rebuffed multiple offers from him for talks.
Over the weekend, Taiwan said its coast guard had faced off with a Chinese coast guard ship near the Taiwan-controlled Pratas Islands, which are strategically located at the top end of the South China Sea.
On Saturday, Taiwan's National Security Council Secretary-General Joseph Wu took to social media to detail the 100 Chinese ships he said were currently in the first island chain, referring to an area running from Japan through Taiwan and into the Philippines.
