Officials of the Ministry of the Interior and Safety preside over an emergency meeting in the government complex in Sejong, Nov. 30, after a 4.0 magnitude earthquake struck off the southeastern city of Gyeongju. Yonhap

A 4.0 magnitude earthquake struck the southeastern city of Gyeongju early Thursday, the state weather agency said, but no damage has been reported.

The quake struck the city, 277 kilometers southeast of Seoul, at around 4:55 a.m. at an estimated depth of 12 km, and five aftershocks followed until 5:50 a.m., according to the Korea Meteorological Administration.

It was the second-strongest quake to occur on the Korean Peninsula or waters around it so far this year.

Fire authorities said they had received 107 reports of shaking as of 5 a.m., but no damage has been reported so far.

Korea Hydro & Nuclear Power Co., the operator of nuclear and hydroelectric plants, said the earthquake had not affected the operations of its nuclear power plants, and they were running normally.

The location is near where the country's strongest-ever earthquake of 5.8 magnitude took place on Sept. 12, 2016.

Within a 50-km radius of the seismic center of Thursday's quake, 418 earthquakes of 2 magnitude or stronger have been reported since 1978.

The interior ministry has raised the alert level of its Central Disaster and Safety Countermeasures Headquarters, the nation's disaster control tower, to Level 1, the lowest stage in the three-stage system.

The third-highest earthquake alert of "vigilance" has also been issued.

Prime Minister Han Duck-soo ordered thorough preparedness against disasters.

The interior ministry convened an emergency meeting to assess the aftermath of the quake.

During the meeting, Minister Lee Sang-min instructed officials to maintain an emergency response posture in cooperation with related ministries and regional governments to promptly assess the damage situation and take necessary measures.

Lee Dol-nam, who runs a convenience store in Gyeongju, said the quake shook his store and shelves quite strongly.

"I was shocked, and everything was trembling intensely," he told Yonhap News Agency. "Although there was no damage, I ran out of the store because I have become anxious about earthquakes since the past one (in 2016)." (Yonhap)