All of President Donald Trump’s campaign staffers who attended his rally in Tulsa, Oklahoma, on Saturday are quarantining this week after interacting with several colleagues who later tested positive for coronavirus, CNN has learned.

“As a precaution staff who made the trip to Tulsa are working remotely, and they will be tested and return working to the office after that,” said Tim Murtaugh, communications director for the Trump campaign, in a call with reporters.

After eight staffers tested positive, several of the campaign’s top officials decided to quarantine for the week instead of going into the office, two sources familiar with the situation told CNN. Staff had only recently returned to the office after months of working from home because of coronavirus restrictions.