The People's Liberation Army of China sent 30 warplanes and five warships toward Taiwan on Monday, the island's defense ministry said.
As of 5 p.m., Taiwan's armed forces have detected five ships and 30 planes of the People's Liberation Army of China, of which 15 have crossed the midline of the Taiwan Strait, the island's defense ministry said in a statement posted on Twitter.
Among the military planes that crossed the so-called midline were one Z-9 anti-submarine helicopter, eight Su-30 fighters, four J-16s and two J-11s.
According to the agency, Taiwan sent an air patrol to monitor the situation and also deployed anti-aircraft missile systems.
Chinese Defense Ministry spokesman Wu Qian said Monday that the Chinese army is again conducting military drills and patrols around Taiwan in response to a visit to the island by a delegation of US congressmen.
A delegation of US congressmen, led by Senator Ed Markey, arrived in Taiwan on Sunday for a two-day visit. It was previously reported that the delegation would meet with senior Taiwanese officials to discuss US-Taiwan relations, regional security, trade and investment, global supply chains, climate change and other important issues of mutual interest.