China sent more fighter jets into Taiwan’s air defence zone on Wednesday in a stepped up show of force around the island Beijing claims as its own, and Taiwan’s foreign minister said it would fight to the end if China attacks.

The democratic self-governed island has complained of repeated military activities by Beijing in recent months, with China’s air force making almost daily forays in Taiwan’s air defence identification zone. On Monday, China said an aircraft carrier group was exercising close to the island.

Taiwan’s defence ministry said 15 Chinese aircraft including 12 fighters entered its air defence identification zone, with an anti-submarine aircraft flying to the south through the Bashi Channel between Taiwan and the Philippines. Taiwan’s air force sent up aircraft to intercept and warn the Chinese away.