The State Administration for Market Regulation, China's top market regulator, announced on Friday night that it has launched an investigation into DuPont China Group, a subsidiary of the US firm DuPont, for suspected monopolistic practices in violation of China's Anti-Monopoly Law.

The move came as China launched on Friday at least 11 strong countermeasures—including a 34 percent tariff hike and export controls on rare earth elements—to fight back against the latest round of bullying tariffs from the Trump administration.

DuPont is a US science and technology company known for innovations in chemicals, materials science, and biotechnology.