Mercedes-Benz sports utility vehicles built in Tuscaloosa, Alabama, are being checked for potential problems by Shanghai customs authorities. Daimler confirmed on Thursday, as a trade dispute between the United States and China heats up.

Reuters reports Mercedes-Benz GLE and GLS models, built in the US between May 4 and June 12, 2018, have a brake issue which poses a “safety risk".

The document said authorities in Shanghai had found the rear brakes on these vehicles to be “insufficient.