Taiwan authorities said on Tuesday afternoon that a Chinese satellite had flown over southern Taiwan’s airspace.
Mobile phone users across Taiwan received an “air raid alert” warning them to “be aware for your safety”.
The satellite was launched off the Xichang Satellite Launch Centre in China’s Sichuan province at 15:03 local time, Taiwan’s defence ministry said.
Chinese broadcaster CCTV confirmed a satellite named Einstein Probe had been launched from the centre.
It added that the launch mission was a “complete success”.
Taiwan’s foreign minister Joseph Wu said the launch of a satellite (over Taiwanese airspace) so close to the election is a “greyzone” activity, Reuters news agency reported.
Taiwan said its defence ministry is tracking the trajectory of the satellite to “appropriately alert and respond” to the situation.
Taiwanese media say this is the first time its government has flashed an islandwide alert of this nature.
Eric Chu, the chairman of Taiwan’s main opposition party Kuomintang (KMT), accused the Democratic Progressive Party’s (DPP) government of fear-mongering, especially with the use of the term “missile” in the English version of the alert. It read: “[Air raid alert] Missile flyover Taiwan airspace, be aware.”
The incident comes days before pivotal presidential and legislative elections in Taiwan, which analysts have said will shape the trajectory of ties between Beijing and Washington.
According to the European Space Agency, the Einstein Probe is a partnership between the agency, the Chinese Academy of Sciences and the Max Planck Institute for Extraterrestrial Physics.
The satellite will “observe mysterious transient phenomena in the universe comparable to the flickering of fireworks, with the aim of unveiling the violent and little-known aspects of the cosmos”, China’s Xinhua news agency said on Tuesday.
In December, Taiwanese media had also reported on Chinese carrier rockets passing over the island. A Focus Taiwan report published on 10 December said a carrier rocket, also launched from Xichang had passed over southwestern Taiwan in outer space.