Six positive cases for coronavirus have been detected at three Premier League clubs after players and staff were tested ahead of a return to training, England's top flight said Tuesday.
"The Premier League can today confirm that, on Sunday 17 May and Monday 18 May, 748 players and club staff were tested for COVID-19," the league said in a statement.
"Of these, six have tested positive from three clubs."
No details were released over which individuals or clubs are affected.
"Players or club staff who have tested positive will now self-isolate for a period of seven days," added the league's statement.
Premier League clubs began returning to training in small groups on Tuesday after protocols on safety measures were signed off on Monday.
The number of positive cases represents just 0.8 percent of those tested and is consistent with similar widespread testing conducted by other major leagues hoping to complete the season.
Germany's top two divisions registered 10 positive cases out of 1,724 tests two weeks ago ahead of their return to action last weekend.
Five players from Spain's top two divisions tested positive last week before La Liga's return to group training.
Premier League clubs are aiming for a return to action by the middle of next month despite concerns from some players over their welfare.
Watford captain Troy Deeney has said he will not return to training this week due to fears he could pass the virus on to his five-month-old son.