HWASEONG, (South Korea): Twenty-two people were killed in a massive fire at a South Korean lithium battery plant on Monday, most of them Chinese nationals, in one of the country’s worst factory disasters in years.

Over 100 people were working in the factory when workers heard a series of explosions from the second floor, where lithium-ion batteries were being inspected and packaged, firefighter Kim Jin-young told media.

In the massive blaze that ensued, 22 people were killed, including 20 foreign nationals — 18 Chinese, one from Laos, and one of unknown nationality, he said.

“Most of the bodies are badly burned so it will take some time to identify each one,” he said, adding that one person was still missing.

Initial investigations indicate that the fire spread in a matter of seconds, with toxic fumes quickly overwhelming workers in the area, said Cho Sun-ho head of the Gyeonggi fire department.

“White smoke began to rise from a battery part, and it took only about 15 seconds to cover the entire space due to the sudden ignition,” he said, adding that as it was a lithium fire, the workers’ efforts to extinguish wouldn’t have worked.

“It is presumed that the victims inhaled toxic fumes in a short time which would have suffocated them quickly, and made them lose consciousness,” he said.

Dozens of fire trucks were lined up outside the factory, an AFP reporter saw, with rescue workers carrying bodies, covered by blue blankets, out of the building on stretchers.

Wearing a green jacket which top officials don during emergencies, South Korea’s President Yoon Suk Yeol visted the disaster site late Monday, walking around the charred building in a hard hat and facemask before greeting firefighters at the scene.