Taiwan Semiconductor Manufacturing Co. evacuated factories following a 6.4 magnitude earthquake near the city of Chiayi that injured at least four people and suspended work at factories across the island’s south.

Chipmaker TSMC said on Tuesday that all its sites were operating following an overnight 6.4 magnitude earthquake in southern Taiwan that was centred on a mountainous rural area and caused only minor damage and light injuries.

At 12:17 a.m. on January 21, a 6.4-magnitude earthquake struck Dapu Township in Chiayi County, Taiwan, with a peak intensity of level 6 (lower). The tremor also reached intensity level 5 (lower) in Tainan and Kaohsiung.