BEIJING (AP) — China has criticized Washington for imposing anti-dumping duties of more than 500 percent on Chinese steel amid mounting tension over complaints Beijing is exporting at improperly low prices to clear a backlog at home.

The Commerce Ministry complained Wednesday that U.S. regulators hampered Chinese companies' ability to defend themselves during an investigation and imposed excessively high penalties. The duties announced Tuesday total 522 percent.

The European Union launched its own investigation of Chinese steel exports last week following protests by steelworkers.

The Chinese government is in the midst of a massive effort to shrink its bloated steel industry. The Cabinet approved measures in April to support steel exporters with tax rebates and bank loans.