Taiwan issued an islandwide air raid alert after a Chinese satellite flew over its southern airspace days before a crucial presidential election.
Mobile phone users across the self-ruled island received a message warning them to “be aware for your safety”.
The “presidential alert” underlined jitters ahead of pivotal presidential and legislative elections on Saturday.
China has long claimed Taiwan as part of its own territory and has been accused of interfering in the vote.
The self-governing island of 23 million people, is a key flashpoint in the tussle between China and the US for supremacy in Asia. Analysts say the elections will shape the trajectory of ties between Beijing and Washington.