*

Up to 70 critical online services still down in heavily

wired

country

*

Lithium-ion battery sparked 'thermal runaway', extreme

heat,

fire official says

*

No estimated time for recovery of government online

services

(Adds LG Energy Solution in paragraph 7)

By Jack Kim

SEOUL, Sept 27 (Reuters) - A major fire at South Korea's

national data centre has crippled some government online

services and internal networks, prompting a race on Saturday to

bring the systems back online and a probe of what sparked a

lithium-ion battery to start the blaze.

The fire is suspected to have started with an explosion on

Friday night of the battery produced by South Korea's LG Energy

Solution during maintenance, damaging some servers

and forcing the shutdown of hundreds of others, officials said.

The fire led to a "thermal runaway", producing extreme heat

in the server room at the National Information Resources

Services in the city of Daejeon, preventing firefighters from

taking aggressive actions to contain the blaze, fire and

government officials said in press briefings.

The national data service acts as a cloud server for many

government services and databases for the heavily wired Asian

country. It operates data centres in other locations.

The fire, which began around 8:20 p.m. (1120 GMT), was

brought under control early on Saturday, but more than 600

servers remained in forced shutdown to protect data while

firefighters worked to extract nearly 400 battery packs from the

building as safety measures, officials said.

The cause of the initial spark was not known and was under

investigation, they said.

LG Energy Solution declined to comment as the case is under

investigation.

Some government ministries, the mobile identification

system, the postal service, and the government legal database

were among websites that remained down on Saturday after the

fire in Daejeon, about 140 km (90 miles) from the capital Seoul.

Some ministries are unable to use email, according to

notices to reporters.

Prime Minister Kim Min-seok apologised on Saturday for the

inconvenience to the public from disrupted services and said the

government would work swiftly to restore services. In the

meantime, tax payment deadlines coming soon would be delayed, he

said.

"There were difficulties in containing the fire because of

the nature of critical government systems being concentrated at

one site," Kim told a televised emergency meeting.

The internal networks of some government agencies in Daejeon

and nearby Sejong were "paralysed", Kim said. There was no

estimate for when services would restart, the head of the data

centre, Lee Jae-yong, told a briefing.

One person has been treated for a minor injury, a fire

official told another press briefing. There was considerable

fire damage at the location of the initial blaze on the fifth

floor of the building, fire official Kim Ki-seon said.