SEOUL (Reuters) -A fire broke out at a lithium battery manufacturing plant in South Korea on Monday, fire officials said, and Yonhap news agency reported that some 20 bodies had been found inside the factory.

The fire, which has largely been extinguished, occurred at around 10:30 a.m. (0130 GMT) at a factory run by battery manufacturer Aricell in Hwaseong, south of the capital Seoul.

The blaze began after a series of battery cells exploded inside a warehouse with some 35,000 units, said Kim Jin-young, a local fire official.

Yonhap said some 20 bodies were found, but Kim told a televised briefing that nine people died and four others were injured, with two in critical condition.

(Reporting by Hyonhee Shin; Editing by Kim Coghill and Miral Fahmy)