JAKARTA, Jan 20 (Reuters) - A fire broke out at a nickel smelter in eastern Indonesia, an official said on Saturday, less than a month after a fire at the same industrial park killed 21 people.

No workers were injured in the late Friday furnace fire at the smelter in Morowali, operated by Sulawesi Mining Investment, said park spokesperson Dedy Kuniawan.

The company shut four furnaces at the smelter on the island of Sulawesi, with three to remain shut for 12 hours and the other to be shut pending investigation and repair, Dedy said.

The Indonesian government said on Tuesday there was a strong indication that a safety procedure violation caused the Dec. 24 fire, which police are still investigating.

Indonesia's nickel processing sector has experienced a number of fatal accidents as it has expanded rapidly since 2020, when the government banned the export of nickel ore to attract investment into its downstream industry.

The Indonesia Morowali Industrial Park, the country's largest nickel hub, sprawls over 3,000 hectares (7,400 acres) and focuses on nickel processing, employing 70,000 workers at dozens of companies.

(Reporting by Fransiska Nangoy; Editing by William Mallard)