An explosion at a steel plant in Baotou city, North China's Inner Mongolia autonomous region, on Sunday left six people dead, 84 injured and four missing, according to the emergency headquarters at the explosion site in Baotou city, Xinhua News Agency reported.

The Office of the Work Safety Commission under China's State Council said it will supervise and handle the investigation of the incident. The Ministry of Emergency Management also dispatched a working group to oversee on-site rescue and cleanup operations.

The blast occurred at 3:03 pm on Sunday in the steel-making department of a plate plant operated by Baogang United Steel in western Baotou, when a 650-cubic-meter saturated water and steam spherical tank exploded.

Of the 84 hospitalized, five are in critical condition and 79 have minor injuries, including facial wounds and soft tissue contusions. All patients are currently stable, Lin Li, Baotou's executive vice-mayor, said at a Monday morning news conference. The local government has suspended production at the plant and launched a citywide emergency response.

The autonomous region's Communist Party of China committee and regional government set up an investigation team led by Bao Gang, chairman of the regional government, to determine the cause and assign accountability. Legal action has already been taken against individuals responsible for the enterprise, officials said.

Inspections within a 5-kilometer radius of the factory confirmed that utilities including electricity, water, gas and communications were unaffected by the explosion.

Residential heating is operational, and surrounding businesses continue to operate.

A thorough check of nearby residential buildings found no structural safety issues. Environmental assessments by the ecological department detected no negative effects on air, soil or wastewater at the site.