An undersea quake measuring 5.5 on the Richter scale struck southern Taiwan on Friday, local seismologists said, but there were no immediate reports of damage or casualties.
The quake hit at 9:39 am (0139 GMT) around 81.2 kilometres (48.7 miles) southwest of Hengchun, a town in Pingtung county, at a depth of 93 kilometres, the island's Seismology Centre said.
The quake could not be felt in the capital Taipei.
Taiwan, which lies near the junction of two tectonic plates, is regularly shaken by earthquakes. A 7.6-magnitude quake killed about 2,400 people in September 1999.