A damaged building is seen in Pohang, South Korea, on November 15, 2017.
An natural disaster measuring 5.4 on the Richter scale jolted South Korea on Wednesday. No casualties have been reported yet.
It's the strongest quake in South Korea since a 5.8-magnitude occurred near the ancient city of Gyeongju, which is close to Pohang, in September 2016, Korea Meteorological Administration officials said.
Samsung and SK hynix experienced temporary suspension of chip production in September a year ago when a more powerful quake struck near Gyeongju south of Pohang.
Before the main tremor, earthquakes of 2.2 and 2.6 magnitude struck areas near Pohang city.
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Myanmar leader Aung San Suu Kyi has come under increasing worldwide pressure to act to prevent further tragedies from occurring. It also denied widespread allegations of sexual violence against Rohingya women or burning down Muslim villages.
According to TV footage, some buildings were externally damaged and windows were broken.
Tremors were felt in the South Korean capital Seoul, around 270km from Pohang, Yonhap added. Students were evacuated from school buildings and people stood on the streets after dashing out of office buildings and apartments.
The nuclear power plant Singori 3 in Ulsan is believed to remain unaffected by the quake.
South Korean President Moon Jae-in was briefed on the quake on his flight to Seoul after ending a weeklong trip to Vietnam, Indonesia and the Philippines.