According to a source with knowledge of the fighter jet program, the Cameri-based facility was closed on March 16 and 17 for “deep cleaning and sanitation" as a precautionary move to prevent the spread of the novel strain of coronavirus — also known as COVID-19 — that has propagated worldwide. The plant is run by Italian defense conglomerate Leonardo.

Defense One was first to publish news about the shutdown, which was confirmed by Defense News.

The other international final assembly and checkout plant, run by Mitsubishi Heavy Industries and based in Nagoya, Japan, is also back to a normal work schedule after a temporary pause from March 9-13, the source said. Meanwhile, F-35 production at Lockheed Martin’s Fort Worth, Texas-based plant continues without interruption.

In a statement, a spokesman for Lockheed Martin, which manufactures the F-35, said that there are no “specific impacts” to the company’s operation or supply chain at this time.

“Across Lockheed Martin, employees with potential exposure are instructed to work remotely and self-quarantine. We have provided guidance to employees and their managers to accommodate flexible work schedules and alternative arrangements where possible,” Trent Perrotto said. “When the circumstances warrant, we deep clean work areas and common spaces in any facility with elevated exposure to COVID-19 and regularly share exposure-prevention protocols to reinforce healthy behaviors.”

The U.S. government’s F-35 Joint Program Office did not immediately respond to a request for comment.