A worker positions a Model S automobile during a battery pack fitting at the Tesla Motors Inc factory in Tilburg, the Netherlands. [Photo/Agencies]

BEIJING - US electric car maker Tesla on Friday started to recall 6,634 Model S and Model X electric cars in China over a parking brake problem, according to China's consumer quality watchdog.

The recall was filed by Tesla Auto Sales (Beijing) Co to the country's General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ).

All the vehicles were manufactured between February and October of 2016, the AQSIQ said in a statement.

The parking brake system in some of those cars may have defective gears that may break once engaged. If the gear were to break, the parking brake cannot be disengaged.

The company will replace defective brake calipers free of charge.