TAIPEI (Taiwan News) — China’s Shandong aircraft carrier and two supporting ships passed through the Taiwan Strait on Saturday (May 27).

Taiwan’s Ministry of National Defense (MND) tweeted it had monitored the three ships heading north along the Taiwan Strait at noon. They were steering along the west side of the median line.

“We are closely monitoring their movements and will respond accordingly,” the MND confirmed.

The news followed a statement earlier in the day saying 10 naval vessels and 33 Chinese military aircraft had been tracked around Taiwan in a 24-hour period.

China has been flying sorties or sailing its warships around Taiwan on a daily basis as it ratchets up tension across the strait. However, the passage of the Shandong through the 180-kilometer-wide waterway is unusual.

The Shandong is China’s first domestically built aircraft carrier and the second in the People’s Liberation Army Navy service after the completion and commissioning of the Liaoning.