The 6.7-magnitude earthquake topples a 16-story building in southern Taiwan, Feb. 6, 2016. [Photo: Xinhua]

Warnings are being issued in Taiwan about the state of many of the buildings on the island.

Engineering experts attending a forum in Taipei this week have warned that over half of the residential buildings across Taiwan built over 30-years ago and face a significant risk of collapse in a strong earthquake.

The warning comes on the heels of the 6.7-magnitude earthquake near the city of Tainan in southern Taiwan which left 116 people dead.

All but two of those killed were in the 16-story Wei Guan building in Tainan, which collapsed during the quake.

The Wei Guan building is one of a number of buildings in Tainan which suffered significant damage due to the quake.

Tainan Mayor Lai Ching-te says at least two of the buildings damaged in the quake are going to have to be torn down.

"Soil liquidation will make houses tilt. This house before us has been evaluated by professors and architects, and it cannot be reinforced by grouting."

Three people responsible for the Wei Guan building's construction have been arrested amid revelations substandard cement and other building materials were used in its construction around 30-years ago.

Engineers in Taiwan have warned that many of the buildings put up across the island during the 1980's may have been constructed with the same safety defects.