German car manufacturer BMW on Tuesday said it will recall a total of 1.6 million diesel cars globally, citing a problem with the exhaust system. BMW said a defect in the car’s exhaust re-circulation unit could lead to sparks while driving and cause fire in “extremely rare cases”.

In August, BMW had issued a note saying it was recalling 1,00,000 diesel vehicles from South Korea after around 30 cars caught fire in the country this year. It had also recalled nearly 3,00,000 cars in Europe the same month. The company on Tuesday said following an examination of engines with a similar technical setup, it would now have to inspect another million vehicles.

“BMW Group investigations have revealed that in the case of some diesel vehicles glycol-leakage from the EGR- [Exhaust-Gas-Recirculation-] Cooler can occur,” the company said in a statement. “In combination with typical soot deposits and the high temperatures normally present in the EGR module, this might result in smoldering particles. This could lead in very rare cases to the melting of the intake manifold and in extremely rare cases result in fire.”

The company added that there was no significant risk to customers. “Nonetheless the BMW Group decided to further reduce even this minor risk by expanding the country-specific technical campaigns,” it added.

Though the company did not specify the model name, it said the vehicles in question were manufactured between August 2010 and August 2017.