Taiwan monitors the Chinese carrier group in the sensitive Taiwan Strait.

According to Taiwan’s defense ministry, on Thursday, the military of Taiwan dispatched troops to monitor a Chinese naval formation that is passing through the strategically important Taiwan Strait under the command of the aircraft carrier Shandong.

In April, the Shandong took part in Chinese military exercises near Taiwan, and only last month, it made another Pacific deployment.

The Shandong-led formation crossed the narrow Taiwan Strait on Wednesday afternoon, according to a statement from the ministry. The construction sailed northward while adhering to the Chinese side of the waterway’s median line, which serves as an unofficial border between the two.

Taiwan and the US both contest China’s claim that it has jurisdiction over the Taiwan Strait and is not an international waterway. The last time the United States sent warships across the strait was last week, and a Canadian frigate joined them.

Taiwan’s defense ministry said that the Chinese carrier group was still traveling north as of Thursday morning. Without providing any details, it stated that Taiwan had sent out “appropriate” soldiers to maintain vigilance.

China’s Ministry of Defense did not immediately answer a request for comment.

After nine days of landing maneuvers in the Pacific Ocean, the Shandong and other navy vessels headed to the South China Sea, according to a statement released by Japan’s defense ministry on Monday.

In June, the 2019-commissioned ship Shandong crossed the Taiwan Strait. Taiwan has grieved over Chinese Air Force jets violating the middle line across the strait several times.

China has increased military activities close to the democratically run island in response to what it describes as “collusion” between Taiwan and the United States. China has never given up using force to subjugate Taiwan. Taiwan’s administration vehemently denies Beijing’s claim to sovereignty.