TAIPEI (Kyodo) -- A magnitude 6.4 earthquake struck southern Taiwan shortly after midnight Monday, damaging buildings and injuring at least 27 people, according to the island's authorities.

The focus of the temblor, which jolted the island at 12:17 a.m., was located in Dapu Township in Chiayi County at a depth of 9.7 kilometers, the fire agency said. There were no immediate reports of deaths.

Multiple aftershocks hit the area early Tuesday morning.

One of the hardest hit areas was the Nanxi district of Tainan, where over 10 houses collapsed or were partially damaged, according to local reports.

Tainan Mayor Huang Wei-che said power outages had affected some areas of the city. He called on residents in Nanxi to stay home to facilitate post-disaster operations.

A 51-year-old Nanxi resident said, "I woke up after a sudden big jolt and smelled gas that may have leaked. I don't know what to do." A wall of the resident's three-story house had collapsed with broken glass pieces scattered across a room.

Authorities have called for vigilance, warning that major aftershocks may occur over the next three days.

Taiwan Semiconductor Manufacturing Co., the world's largest contract chipmaker, has evacuated its employees from several factories in central and southern Taiwan following the powerful quake and they are all safe, according to local reports.