There were no immediate reports of deaths from the quake, though rescuers were still assessing damage.
Taiwan’s fire department said 15 people were sent to hospital for minor injuries. Among them were six people, including one child, who were rescued from a collapsed house in Nanxi District, Tainan city. The Zhuwei bridge on a provincial highway was reported to be damaged.
Last April, a magnitude 7.4 quake hit the island's mountainous eastern coast of Hualien, killing at least 13 people and injuring more than 1,000 others. The strongest earthquake in 25 years was followed by hundreds of aftershocks.
Taiwan lies along the Pacific “Ring of Fire,” the line of seismic faults encircling the Pacific Ocean where most of the world’s earthquakes occur.