Key Points

The fire broke out at the National Information Resources Service in the central city of Daejeon after a lithium-ion battery exploded in a computer room on the fifth floor.

Officials said the explosion occurred in one of the centre's uninterruptible power supply batteries while staff members were working to relocate them to the basement.

The fire left 647 online government services and systems down as of Saturday morning, including the mobile identification system and online postal service, according to officials.

South Korean Vice Interior Minister Kim Min-jae said the government suspended operations as a "preemptive" measure to safeguard the systems after the fire caused temperature and humidity control malfunctions that can lead to overheating.

"The temperature and humidity control equipment is currently being repaired. Once this is complete, the government plans to bring the servers back online to restore the services," Kim said at a press conference, adding that critical services like postal and financial services will be restored first.

The disruptions paralysed the location-tracking function of the 119 emergency rescue service, the online official document issuance service and the pan-government intranet, Onnara System, leaving government officials unable to access the online administration systems.

The websites of major government bodies, including the office of the prime minister and the interior and finance ministries, also remain inaccessible.

The disruptions are believed to have paralysed nearly one-third of the government's total online information systems.

Citizens reported inconveniences caused by the service disruptions. A 53-year-old, surnamed Lee, attempted to make a payment with a debit card issued by Korea Post at a convenience store in Uijeongbu, north of Seoul, but found it did not work.

Others also said that the money transfer service on Korea Post financial accounts was unavailable, Yonhap news agency reported.

Nearly 10 hours after the breakout, the main blaze of the fire had been brought under control as of 6:30 a.m., but it partly reignited later in the morning.

Firefighters were working to ventilate the building. About 200 firefighting personnel were mobilised, along with dozens of fire trucks and other equipment.

One worker handling the batteries sustained first-degree burns to the arms and face, while nearly 400 lithium-ion battery packs inside the room were destroyed in the fire.

At an emergency meeting Saturday morning, South Korean Interior Minister Yun Ho-jung raised the crisis management level for government information systems from "alert" to "serious."

"The government will mobilise all available resources to resolve this incident as quickly as possible while doing its best to minimise inconveniences to the public," Yun said.

South Korean Prime Minister Kim Min-seok apologised for the service disruptions, saying the government will work to restore the affected services.

- IANS