A digital billboard in Des Moines, Iowa, warns President Donald Trump’s upcoming rally will be a “superspreader event.” The campaign event will be held Wednesday at Des Moines International Airport.

The billboard, which went up on Tuesday, was sponsored by advocacy group Rural America 2020.

“Rural America 2020 educates Americans on how policies affect rural America. We are working to highlight misguided policies that have left rural communities behind and to advocate for policies that will benefit rural Americans and their communities,” the group’s website says. 

Chris Henning, an Iowa Rural America 2020 Steering Committee member, in a press release called the rally “the height of irresponsibility.” Up to 10,000 people could attend the event. 

Trump campaign communications director Tim Murtaugh defended the rally, saying attendees will have their temperatures taken prior to the event. Rally goers will also be provided masks and hand sanitizer, he said.

Trump on Monday held his first rally since his COVID-19 diagnosis at an airport outside of Orlando, Florida. Many of the attendees did not wear masks. 

On June 20, Trump held a rally in Tulsa, Oklahoma, after spending several months off the campaign trail. Local authorities later said the event “likely” contributed to a surge in COVID-19 cases.

Dr. Anthony Fauci, the nation’s top infectious disease specialist, has advised against the rallies.

Trump has stated that he aims to hold a campaign event every day until the Nov. 3 election. 

Iowa has struggled to contain the virus. On Monday, the Iowa Department of Public Health reported over 100,000 total cases across the state with the death toll approaching 1,500.