Taiwan's air force scrambled on Friday to warn away 10 Chinese aircraft that entered its air defence zone, Taiwan's defence ministry said, the day after the island announced a US$9 billion boost to military spending to counter the threat from China.

Chinese-claimed Taiwan has complained for a year or more of repeated missions by China's air force near the democratically governed island, often in the southwestern part of its air defence zone close to the Taiwan-controlled Pratas Islands.

The latest Chinese mission involved...