Safety barricade gates are opened for supporters to enter for President Donald Trump’s campaign rally Saturday, June 20, 2020 in Tulsa, Oklahoma

Six members of the advance team staffing the rally of U.S. President Trump in Tulsa Oklahoma have tested positive for the coronavirus.

The confirmed cases underscored concerns by health experts about holding a massive indoor event in a city where cases are spiking.

The campaign said quarantine procedures had gone into effect for the infected staff members and those in “immediate contact” with them, Washington Post reports

Upon entering the rally grounds, attendees were handed blue face coverings — which many chose not to wear — and directed through a maze of metal fencing, which led to a touchless temperature screening conducted by volunteers in purple smocks.

Outside the security perimeter, arguments erupted between protesters and the president’s supporters at street corners near the arena, where they traded cries of “Black lives matter” and “all lives matter.”

One protester was arrested at the 19,000-seat BOK Center, a private venue leased by the Trump campaign.