Soldiers rehearsed urban defense operations, made use of the Taipei Metro for tactical mobility and repurposed schools as command posts. The drills began with a simulated "gray zone" cyberattack that took out Taiwan's central command.

Taiwan's annual military exercise, Han Kuang, begins on Wednesday as the island ramps up its defence against a possible invasion from China. Billed as the largest and longest one so far, this year's Han Kuang will last for about 10 days, about twice the duration of last year's drill.

The 41st Han Kuang exercise is taking place against a backdrop of heightened tensions with China, which claims Taiwan as its own and has vowed to unify with it—by force, if necessary. This year's live-fire component is the longest ever, reflecting the seriousness with which Taipei views the threat.