Six members of US President Donald Trump's campaign staff tested positive for the coronavirus on Saturday ahead of a major rally in Tulsa, Oklahoma, NBC News first reported.The diagnoses were confirmed in a statement by Trump's campaign communications director, Tim Murtaugh. "Per safety protocols, campaign staff are tested for COVID-19 before events," he said. "Six members of the advance team tested positive out of hundreds of tests performed, and quarantine procedures were immediately implemented. No COVID-positive staffers or anyone in immediate contact will be at today's rally or near attendees and elected officials. As previously announced, all rally attendees are given temperature checks before going through security, at which point they are given wristbands, face masks and hand sanitizer."The campaign is conducting contact tracing on the confirmed cases.The diagnoses add further fuel to the controversy that Trump has faced over his rally in Tulsa – which is being held in an enclosed, 19,000-seat arena – over fears that it could lead to the further spread of COVID-19.This criticism was reflected by concerns voiced by the top US infectious disease expert Dr. Anthony Fauci and coronavirus task force response coordinator Dr. Deborah Birx over holding the rally in Oklahoma. This is because the state has seen a significant rise in coronavirus cases, with Tulsa County having had a 100% increase in cases over the past week and having recorded its highest daily rise in confirmed cases on Saturday, NBC News reported.This is made worse by allegations made to NBC News by undisclosed sources familiar with the situation, who claimed that members of Trump's campaign staff have been in the city for a week and have been flouting coronavirus restrictions, even eschewing the use of masks.In addition, the Trump campaign has required everyone attending the rally to sign a digital waiver that absolves Trump and the campaign of any liability if they get sick.