South Korea's meteorological agency said Thursday that an aftershock exceeding the magnitude 5.8 quake that jolted the country's southeastern region is unlikely to occur, although more moderate tremors can happen for a while.

The announcement by the Korea Meteorological Administration came a day after a magnitude 3.5 aftershock hit region near Gyeongju, some 371 kilometers southeast of Seoul. This followed two strong earthquakes that hit the city on Sept. 12. The larger quake, which was felt throughout South Korea, was the strongest ever recorded on the Korean Peninsula.

Wednesday's quake was one of the stronger aftershocks among 423 tremors detected as of 2 p.m. Thursday since the two big quakes hit the historical city, the KMA said during a press briefing held at its office in Seoul.

The weather agency said aftershocks of magnitude between 3.0 and 4.0 can occur down the road, though it could not predict when they will end.

The KMA said it will dispatch a task force in charge of on-site studies to the city. The team, comprised of scholars and other experts, will analyze the influence of the series of quakes until the end of March.

Meanwhile, the weather agency corrected the epicenter of the

5.8 quake to 8.7 km southwest from the city from the originally reported 8 km. The epicenter of the first quake that happened less than an hour before the strongest one was also corrected from 9 km southwest from the city to 8.2 km away.

The meteorological agency also said it will reduce the time it takes to send alert messages to the public.

There have been calls to improve the current system as the alert messages did not immediately reach the residents near the quake-hit region when they occurred.

The KMA plans to directly send the warning messages starting in November in the event of an emergency. At present, the notification goes through the Ministry of Public Safety and Security, a process which has been cited for causing the delay.

The KMA said it will also increase the number of seismic stations in the country to 315 by 2018 from the current 206.  (Yonhap)