The US Open women's semifinal match between No. 6 seed Coco Gauff and No. 10 Karolina Muchova was interrupted during the second set due to a disruption in the crowd. The players left the court as security took care of the situation high up in the stands.

Climate change protesters were allegedly yelling "end fossil fuels" and security was called to the row where they were sitting. Three protesters left, but there was one remaining who glued his feet to the cement floor.

"Three of the four protesters were escorted out of the stadium without further incident. The fourth protester affixed their bare feet to the floor of the seating bowl," read an official statement by the US Open. "Due to the nature of this action, NYPD and medical personnel were needed in order to safely remove this individual from the stadium. The four protesters were taken into NYPD custody."

Gauff had already taken the first set, 6-4, and was up 1-0 in the second. Initially, Muchova sat down and asked for a trainer and a doctor. Gauff tried to stay active and practiced her serve. 

Players were told they could leave, but Gauff's coaches told her to stay on the court.

"They said they're on the phone negotiating like it's a hostage situation," Gauff told her box.

A few minutes later, both players left the court. 

About 10 NYPD officers surrounded the protester and escorted him out after about 40 minutes. Players were then allowed back on the court and were given time to warm up again before resuming their competition.

"There is no doubt in a 24,000-seat stadium, hopefully people don't get ideas or continue," US Open tournament director Stacey Allaster said on the ESPN broadcast. "We know in these large events environmental protesters use the platform."

Allaster said security and NYPD will work together to see what else can be done to prevent it in the future.