Taiwan was hit by a series of at least 10 earthquakes in the early hours of Saturday, with the strongest reaching 6.1 magnitude, according to the island's Central Weather Administration.
No tsunami warning reports followed the earthquakes, which triggered mobile phone alarms in capital Taipei, an AFP journalist said, and came just several days after dozens of quakes shook the island.
It was followed by several smaller shocks before another strong quake at 2:49 am (1849 GMT), which occurred on land around 40 kilometers from Hualien City on the east coast, at a depth of 18.9 kilometers.
A total of ten quakes of varying magnitude were recorded after midnight on Saturday, according to Taiwan's weather agency.
The National Fire Agency said there were no immediate reports of damage.
The spate comes after buildings in Taiwan were left swaying at the beginning of the week by a series of quakes, with one reaching 6.3 magnitude in eastern Hualien.
The government said they were aftershocks from a deadly magnitude-7.4 quake that hit the island more than two weeks ago, which Taiwan said was the "strongest in 25 years."
At least 17 people were killed after the quake triggered landslides that blocked roads and severely damaged buildings around the main Hualien city.