The state-run Xinhua News Agency said the blast late on Monday night in Anshan city in Liaoning province happened when a mold exploded in a steel-casting plant.
The cause of the explosion was not given.
Rapid economic growth and lax safety measures mean that industrial accidents are relatively common in China.
COMMENT RULES: Comments that are judged to be defamatory, abusive or in bad taste are not acceptable and contributors who consistently fall below certain criteria will be permanently blacklisted. The moderator will not enter into debate with individual contributors and the moderator’s decision is final. It is Belfast Telegraph policy to close comments on court cases, tribunals and active legal investigations. We may also close comments on articles which are being targeted for abuse. Problems with commenting? email@example.com