At least 22 people have been killed in a powerful explosion that ignited a deadly fire at a lithium battery factory in South Korea on Monday, authorities said.

The blaze, which has now been extinguished, ripped through a lithium battery plant, owned by a South Korean primary battery manufacturer, located in Hwaseong, just south of the capital Seoul, Reuters reported.

According to fire fighter Kim Jin-young, a series of battery cells exploded inside a warehouse with some 35,000 units setting the facility ablaze. However, he said that it was nuclear what had triggered the explosions.

He also revealed that among the deceased, 18 were Chinese nationals.

Images shared by the Yonhap news agency showed huge plumes of billowing grey smoke rising into the sky above the factory, with orange flames inside the building. Dozens of fire engines were seen outside.

Fire and Disaster Prevention professor at Daejeon University, Kim Jae-ho, said the fire had probably spread too quickly for workers to escape.

"Battery materials such as nickel are easily flammable," he said. "So often, there is not enough time to respond, compared to a fire caused by other materials."

President Yoon Suk Yeol was monitoring the situation, his office said, while Interior Minister Lee Sang-min called on the local authorities to take steps to prevent any hazardous chemicals from contaminating the surroundings.

Aricell, the company that owned the plant, was established in 2020 and makes lithium primary batteries for sensors and radio communication devices. It has 48 employees, according to its latest regulatory filing and its Linkedin profile.

South Korea is a major producer of batteries, including those used in electric vehicles. Its battery makers supply electric vehicle makers around the world, including Elon Musk's Tesla.