Ford briefly closed two of its major assembly plants in the U.S. on Wednesday over positive coronavirus tests and a parts shortage.

It is understood that Ford closed its Dearborn, Michigan factory following a positive Covid-19 test for one worker. Ford spokeswoman Kelli Felker added that its Chicago assembly plant was also closed due to a parts shortage.

Ford previously closed its Chicago plant twice on Tuesday after two workers on different shifts tested positive for coronavirus. The latest closure happened after a Lear Corp factory in Hammond, Indiana, which makes seats for Ford’s Chicago plant, idled its assembly plant, The Wall Street Journal reports. Late Wednesday, Lear said it idled the plant because of a positive Covid-19 test.

Read More: Ford, GM And FCA Restart Production In U.S., Canada And Mexico

Felker says that all coronavirus exposure impacting the Dearborn and Chicago factories occurred outside the workplace and both sites were expected to resume production later on Wednesday.

These temporary closures come just two days after Ford, as well as other car manufacturers, re-opened production plants throughout the United States.

Ford has employed a host of safety measures to try and keep its employees safe while stopping the spread of the coronavirus. It is screening employees entering its facilities while also mandating the use of face masks and face shields as well as employing social distancing practices along the assembly line wherever possible.

GM and FCA, who also re-opened dozens of plants throughout North America on Monday, have yet to report any issues.

Ford released these images upon opening their factory on Wednesday