It was the latest of a series of deadly accidents at nickel smelting plants in Indonesia that are part of China’s ambitious transnational development programme known as the Belt and Road Initiative.

“Based on initial investigations, the explosion [was] possibly caused because there was still some explosion-inducing liquid at the bottom of the furnace. During the repairing process, an explosion occurred,” an IMIP spokesperson said.

The first explosion triggered several other explosions because there were many oxygen cylinders used for welding and cutting furnace components for the repair, the spokesperson added.

IMIP is a nickel-focused industrial estate owned by China’s Tsingshan and its local partner Bintang Delapan Group, which produce stainless steel and carbon steel. ITSS is one of the tenants at the industrial estate, IMIP said.

IMIP will coordinate with related parties to investigate the incident and cover all treatment costs for victims, the company said.

“We sincerely apologise for this incident and we are working closely with authorities to investigate what caused the accident,” said company spokesperson Deddy Kurniawan.

Nickel has become increasingly crucial for resource-rich Indonesia, the world’s biggest nickel producer, with billions of dollars of global investment flowing in after the government banned exports of unprocessed ore in 2020.

Southeast Asia’s biggest economy is trying develop downstream nickel industries and lure big-ticket investment from manufacturers of electric vehicles and their batteries.

However, several fatal accidents have occurred in Indonesia’s nickel processing industry in recent years. President Joko Widodo is keen to develop the sector but has also called for improvements in safety and has pledged to enhance monitoring of environmental standards.

This was the third deadly accident this year at Chinese-owned nickel smelting plants in Central Sulawesi province, which has the largest nickel reserves in Indonesia.

Two dump truck operators were killed when they were engulfed by a wall of black sludge-like material following the collapse of a nickel waste disposal site in April.

In January, two workers, including a Chinese national, were killed in riots that involved workers and security guards at a Indonesia-China joint venture in North Morowali regency.

Last year, a loader truck ran over and killed a Chinese worker while he was repairing a road in PT IMIP’s mining area, and an Indonesian man burned to death when a furnace in the company’s factory exploded.

Nearly 50 per cent of PT IMIP’s shares are owned by a Chinese holding company, and the rest are owned by two Indonesian companies. It began smelter operations in 2013 and is now the largest nickel-based industrial area in Indonesia.

Three Chinese workers last month filed a complaint to Indonesia’s National Commission on Human Rights, alleging that their health is deteriorating due to dust and smoke exposure while working seven-day weeks without a break at PT IMIP. They added that workers there don’t have adequate safety equipment.

Data collected by the Mining Advocacy Network, an Indonesian watchdog, showed that at least 22 workers from China and Indonesia have died in nickel smelting plants in Central Sulawesi province since 2019, including two Chinese nationals who committed suicide.