BEIJING: China’s Fujian maritime safety administration launched a three-day special joint patrol and inspection operation in the central and northern parts of the Taiwan Strait that includes moves to board ships, it said on its WeChat account.

The move comes amid heightened tensions between China and Taiwan, with U.S. House Speaker Kevin McCarthy hosting Taiwanese President Tsai Ing-wen in California on Wednesday, becoming the most senior U.S. figure to meet a Taiwanese leader on U.S. soil in decades.

The maritime safety authority in the southeastern Chinese province said on Wednesday the operation included “on-site inspections” on direct cargo ships and construction vessels on both sides of the Taiwan Strait “to ensure the safety of vessel navigation and ensure the safe and orderly operation of key projects on water”.

Taiwan’s Transport Ministry’s Maritime and Ports Bureau said in a statement late Wednesday said it has lodged a strong protest with China about the move.

It said it has notified relevant shipping operators that if they encounter such requests from China they should refuse them and immediately notify Taiwan’s coast guard to render assistance.

“If the mainland side insists on taking one-sided actions, it will create obstacles to normal exchanges between the two sides. We will be forced to take corresponding measures,” it added, without giving details.

Areas covered by the operation include the Pingtan Taiwan direct container route, the “small three links” passenger route, the Taiwan Strait vessel customary route, the densely navigable areas of commercial and fishing vessels, and areas with frequent illegal sand mining activities.

The “small three links” passenger route refers to boat routes between Taiwan’s Kinmen and Matsu islands which sit opposite China and Chinese cities.

The fleet, a joint special operation with East China Sea Rescue Bureau and the East China Sea Navigation Support Center, will continue to carry out cruise inspections in the central and northern parts of the Taiwan Strait over the next two days.