The death toll from a powerful shallow earthquake in southern Taiwan has risen to at least seven people, but rescuers are working against time to find survivors under the rubble of collapsed buildings.

Rescuers pulled 247 survivors from the rubble in the city of Tainan, and more than 1,200 firefighters scrambled with ladders, cranes and other equipment to the ruins of a 17-floor residential building that collapsed because of the earthquake.

Local media said the building included a care center for newborns and mothers, and a newborn was among the dead in the disaster, which came two days ahead of the Lunar New Year celebrations.

The 6.4-magnitude temblor struck about 4am local time (2000 GMT on Friday). It hit 35 kilometres southeast of Yujing, and about 10 kilometres underground, according to the US Geological Survey.

The emergency response centre said seven people were killed, including a 10-day-old infant, a small child and at least two other residents inside the high-rise. One death was caused by falling objects. No details were immediately available for the two additional deaths. ↓

Rescuers pulled out 247 survivors, the emergency centre said. Seventy-three people were sent to hospitals, the center said.

The Hong Kong Observatory said the temblor had an intensity of 4 on the MMI scale, which ranks earthquakes 1 to 10, with 10 being the most destructive.