Daejeon, March 21 : Ten people have been killed and four others are still reported missing in a large fire at a car parts plant in South Korea's Daejeon, authorities said Saturday. Another 59 people suffered serious or slight injuries.

Firefighters have been searching for the four people who were unaccounted for when the blaze started.

One of the bodies was found on the second floor of the factory and nine others were found on the third floor, according to authorities.

A total of 170 workers were inside the plant when the fire was reported at around 1:17 p.m. on Friday. The fire prompted the National Fire Agency to issue a national firefighting mobilisation order, which is given when the scale of the fire is deemed to surpass the firefighting capacity of the local government.

Firefighters were earlier unable to enter the structure due to concerns it could collapse. Also complicating the firefighting effort was 200 kilograms of sodium inside the building, which could explode if poorly handled, Yonhap news agency reported.

Authorities said they began overnight search operations at around 10:50 p.m. on Friday after experts determined it was safe for firefighters to enter the building.

An official at the authorities said firefighters plan to make all-out efforts to rescue those who are unaccounted for.

"We plan to tear down the structures where the rescue dogs have already examined to deploy rescue workers and continue the search for those missing," the official said.

On Friday, South Korean Prime Minister Kim Min-seok gave emergency instructions to the interior ministry and the fire agency to use all available equipment and personnel to rescue people and extinguish the fire, his office said.

He had ordered the Daejeon metropolitan government and the police to ensure no further damage by implementing traffic control and evacuation measures.

/IANS