Unionized workers at Hyundai Motor have gone on strike for a sixth consecutive year seeking improved working conditions.

Workers at the country’s largest automaker walked off the job for two hours Thursday morning, and held a separate two-hour rally later in the day.

Hyundai estimates the partial strike delayed the production of around one-thousand-500 cars, losing the company about 30 billion won, or 26-point-three million U.S. dollars.

The union plans to stage two more partial strikes on Monday.