Nuclear power plants in the southern parts of South Korea were not affected by a powerful magnitude-5.8 earthquake that hit the Korean Peninsula on Monday evening, officials said.

The Korea Nuclear Power Co., which operates the country's nuclear plants, said a plant near the epicenter in the historic city of Gyeongju, and other plants in the adjacent areas are fully functional and normally producing electricity.

The record tremor that occurred at 8:32 p.m. was the strongest one to hit the Korean Peninsula to date, according to weather officials. The quake was preceded by a 5.1-magnitude tremor detected earlier in the same area located some 9 kilometers south of Gyeongju, about 400 kilometers southeast of Seoul.

"Despite two tremors in Gyeongju, the Wolseong, Gori, Hanwool and other plants in southern South Korea are in full operation without any problem," said an official at the Korea Nuclear Power.

The official said the power plants were built to withstand an earthquake with a magnitude ranging between 6.5 and 7.

A liquefied natural gas (LNG) power plant in Ulsan, located about 410 kilometers southeast of Seoul, meanwhile, had its operations suspended following the earthquake, energy officials said.

The Ministry of Trade, Industry and Energy said the plant was designed to stop operation in the wake of any minor tremor, noting that it is in the process of looking into the cause.

"Three other LNG power plants were temporarily stopped when the earthquake occurred," said an official, noting that there is no damage reported.

The ministry has set up an emergency team to deal with any aftermath from the earthquake and dispatched vice minister Woo Tae-hee to Gyeongju to examine situations related to the nuclear facilities.

 South Korea's leading oil refiners SK Innovation and S-Oil also said that their oil refining and petrochemical plants in Ulsan, close to the epicenter in Gyeongju, sustained little damage from the tremor.

Ulsan's industrial complex is the home to a number of petrochemicals plants, including SK's CLX plant, S-Oil's oil-refining facility and interior and automotive materials maker LG Hausys.

Industry officials said that no reports of earthquake-related damage, like operational suspension or facility collapse, have been compiled by the oil and petrochemicals plants in Ulsan.

"Ulsan's CLX plant has not reported anything extraordinary thus far," said an official at SK Innovation, noting the facility was designed to withstand an earthquake of magnitude 7.

Officials at S-Oil and LG Hausys also said their plants in Ulsan have not developed any problems related to the quake.

Meanwhile, mobile carriers said temporary communications disruptions and delays were reported in some regions of the nation on Monday evening following the quake due to a surge in phone calls and SNS communications but their networks returned to normal later.

Mobile instant messaging service Kakao Talk and Internet services also underwent some disruptions in some areas but the problems were resolved later as the situation stabilized, said industry officials. (Yonhap)