The owners of the 30 tracks that host NASCAR events have asked fans not to display Confederate flags at their respective facilities.

In a statement issued Thursday, the track owners said they join NASCAR “in the desire to make our events among the most fan-friendly, welcoming environments in all of sports and entertainment. To do that, we are asking our fans and partners to join us in a renewed effort to create an all-inclusive, even more welcoming atmosphere for all who attend our events.”

NASCAR has come under increasing scrutiny in recent weeks for permitting fans to bring and display Confederate flags on their cars and recreational vehicles.

The Confederate flag is seen by some as a racist symbol.

NASCAR chairman Brian France and drivers Jeff Gordon and Dale Earnhardt, Jr. have all called for the state of South Carolina to remove the Confederate flag from the statehouse grounds in Columbia, after a 21-year-old man allegedly shot and killed nine people two weeks ago in a Charleston church. The alleged shooter had displayed the Confederate flag and other white supremacist symbols.

Joie Chitwood III, Daytona Motor Speedway president, offered to exchange Confederate flags with U.S. flags this weekend, when the Daytona track hosts NASCAR events on Saturday and Sunday.