With fears mounting over a trade war between the U.S. and China, Beijing has launched antidumping investigations on phenol imports from the U.S., South Korea and Japan. 

China’s Commerce Ministry announced in a statement that it began the antidumping probe on Monday at the request of domestic companies, including the China National Petroleum Corporation. The probe will also look into phenol imports from the European Union and Thailand.

In a request submitted earlier in February, Chinese companies claimed that phenol imported from the U.S. and South Korea was being sold in the Chinese market at prices lower than exporting countries normally charge in their home markets. The Chinese businesses said that as a result they suffered substantial losses, including falling market shares and profits.