Taiwan’s coast guard held drills with the military on Sunday to better practice joint operations in the face of what the government in Taipei says is a growing “grey zone” threat from China, which claims the island as its own territory.

Democratically governed Taiwan has repeatedly complained about activities such as undersea cable cutting and sand dredging by China around the island, designed to pressure it without direct confrontation.

It is often Taiwan’s coast guard that scrambles first to respond.

The drills in the southern port city of Kaohsiung, overseen by President Lai Ching-te, simulated the seizing of a ferry by “international terrorists”. The coast guard worked with an interior ministry rescue helicopter and army medevac helicopter to board and take back control of the boat and evacuate casualties.

A navy anti-submarine helicopter flew over the scene as the drill ended, along with the medevac and rescue helicopters, the first time they have flown together in such a scenario, the coast guard said.