According to an internal notice and two people who know the matter, Tesla stopped production at its Shanghai plant Saturday.

The U.S. automaker Tesla had canceled the morning shift. It informed all workers at its most efficient manufacturing hub that they could begin their break. The company didn’t give any reason.

Reuters reported that the electric car company planned to stop Model Y production from Dec. 25 through Jan. 1.

This suspension is part of a growing wave of infections following China’s recent relaxation of its zero-COVID policy. While the public welcomed this, it severely disrupted business operations short term.

Tesla China’s media representative did not respond immediately to a request for comment.

According to Reuters, the plant’s suspension at the end of Model Y assembly would be part of a reduction in the production of 30% in the month. This is Tesla’s most-sold model at the Shanghai factory.

The Shanghai factory, Elon Musk’s most important manufacturing center, continued normal operations in the final week of December. The plant has never been allowed to close down for a holiday at the end of the year.

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