SEOUL - South Korean fire department officials said late Monday night that around 17 Chinese nationals were killed in the Hwaseong battery plant fire the day earlier, but the exact number still needs to be further confirmed.

South Korean officials, including Gyeonggi province Second Vice-Governor Oh Who-seok, Hwaseong City Mayor Jeong Myeong-geun, and officials from the fire department, briefed Chinese Ambassador to South Korea Xing Haiming on the accident and the progress of search and rescue efforts at the scene.

Park Soon-kwan, the CEO of lithium battery manufacturer Aricell, which the factory belongs to, offered condolences to the workers who were killed. Park apologized to everyone who had been affected by the accident, but said the company had complied with all required safety precautions and training.

"We will be conscientiously taking part in the investigation by authorities and will do our best to determine the cause of the accident and to take measures to prevent a repeat of such an accident," Park told reporters at the scene of the fire.

Xing urged the South Korean side to find out the cause of the accident as soon as possible, properly deal with the aftermath, and provide all necessary support for the families of the Chinese victims

South Korean officials said the accident has killed 22 people, 17 of them presumably to be Chinese nationals. Eight other people were injured, including one Chinese who was slightly injured, and all the injured have been properly treated. Firemen are still searching for the missing.

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The South Korean side deeply mourns the tragic death of Chinese citizens in the accident and will assist China in doing its utmost to rescue and deal with the aftermath.

Xing urged the South Korean side to find out the cause of the accident as soon as possible, properly deal with the aftermath, and provide all necessary support for the families of the Chinese victims.

Xing told media at the scene that the Chinese embassy is working with the South Korean side to do its best to deal with the aftermath of the accident. It is hoped that South Korean businesses will learn a painful lesson, refrain from similar incidents in the future and earnestly safeguard the safety of Chinese citizens in South Korea.

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The blaze was first reported at 10:31 am (0131 GMT) after a series of battery cells exploded inside a warehouse of 35,000 batteries, according to Kim Jin-young, an official at the Hwaseong fire service.

The victims likely succumbed to extremely toxic gas within seconds of the blaze getting out of control, local fire officials said. It was unclear what caused the explosions and the fire was largely extinguished in about six hours.

Gyeonggi province fire official Cho Sun-ho said smoke and the fire blaze spread within 15 seconds and the victims likely succumbed after taking one or two breaths

Live TV footage showed firefighters spraying the damaged steel and concrete building. Parts of the upper level had collapsed, and large chunks of the building looked like they had been blown out into the street by explosions.

Aerial footage showed massive white smoke clouds billowing from the structure and explosions rolling through the building.

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Gyeonggi province fire official Cho Sun-ho said most of the foreign workers killed were temporary hires, likely unfamiliar with the structure of the building. Smoke and the fire blaze spread within 15 seconds and the victims likely succumbed after taking one or two breaths, he said.

South Korea is home to major producers of lithium-ion batteries that power electric vehicles (EVs) and to one of the world's biggest automakers, Hyundai Motor, and its affiliate Kia.

Two years ago South Korea brought in legislation to punish the executives of a company in the event of a fatal accident with possible jail terms after the country saw dozens of workers killed in industrial accidents each year.

With Reuters inputs