A massive explosion at a steel plant has left four dead, 84 injured and six missing, local authorities in Baotou city said at a news conference on Monday morning, reported China Central Television.

The incident occurred at 3:03 pm on Sunday in the steel-making department of a rare earth steel plate factory operated by Baogang United Steel in Baotou, Inner Mongolia autonomous region.

Emergency response teams, including fire, emergency, police, health, and market regulation departments, have been deployed to conduct search and rescue operations, provide medical treatment, and support affected families.

A medical team is overseeing the treatment of the injured. Of the 84 hospitalized individuals, five are in critical condition, while the remaining 79 have minor injuries. All patients are currently stable, according to the regional health commission's expert team.

An investigation team has been established to determine the cause of the incident and assign accountability. Authorities have pledged to hold those responsible accountable, with no tolerance for negligence.

Legal actions have already been taken against relevant company personnel.

Rescue operations continue as teams work to locate the missing individuals and treat the injured. The cause of the explosion is under investigation.