NASCAR has confirmed that a noose was found in driver Bubba Wallace’s garage stall on Sunday (June 21). Wallace is the only African American driver in the organization’s top circuit and has been a vocal supporter of the Black Lives Matter movement.

The news arrives a few days after Wallace called on NASCAR to ban all Confederate flags from their races, which they did on Wednesday (June 10).

“We are angry and outraged, and cannot state strongly enough how seriously we take this heinous act,” NASCAR wrote in a statement. “We have launched an immediate investigation, and will do everything we can to identify the person(s) responsible and eliminate them from the sport.”

The organization added that the incident “only strengthens our resolve to make the sport open and welcoming to all.”

CNN reports that the noose was found in a restricted garage area where only essential personnel are allowed, including race teams, NASCAR officials, security staff and health and safety personnel.

“Today’s despicable act of racism and hatred leaves me incredibly saddened and serves as a painful reminder of how much further we have to go as a society and how persistent we must be in the fight against racism,” Wallace — who’s credited as one of NASCAR’s most successful African American drivers ever — tweeted about the incident.

“Over the last several weeks, I have been overwhelmed by the support from people across the NASCAR industry including other divers and team members in the garage. Together, our sport has made a commitment to driving real change and championing a community that is accepting and welcoming of everyone. Nothing is more important and we will not be deterred by the reprehensible actions of those who seek to spread hate.”

“As my mother told me today, ‘They are just trying to scare you.’ This will not break me, I will not give in nor will I back down,” he wrote. “I will continue to proudly stand for what I believe in.”

According to CNN, despite the Confederate flag being banned from the racetrack, fans were seen selling Confederate memorabilia across the street before the event. The race was reportedly postponed to Monday (June 22) due to weather concerns.