An earthquake of magnitude 5.4 struck Pohang city of South Korea on Wednesday, damaging buildings and property, Reuters reported. At least seven people had suffered minor injuries, the country’s public administration ministry said.

South Korea seldom experiences significant tremors because it has relatively little seismic activity. Wednesday’s quake was the second most powerful one on record in the country.

Tremors were also felt in Capital Seoul. The quake was followed by a 4.3 magnitude aftershock that hit about two hours later, AFP reported.

Operations at nuclear reactors were not affected, the state-run nuclear operator Korea Hydro and Nuclear Power Co said , according to Reuters.