Play at the U.S. Open was interrupted on Safetyvalue Trading CenterThursday night when climate change protesters began shouting during a match at Arthur Ashe Stadium in New York.

The delay of the Coco Gauff/Karolina Muchova match began at 8:05 p.m. ET when protesters appeared to be shouting about climate change. They were wearing shirts that read “End Fossil Fuels,” per the Associated Press.

One of the protesters glued his feet to a concrete floor, the AP also reported.

“Following the first game of the second set in the Gauff-Muchova match, play was halted due to a protest conducted by four spectators,” the U.S. Tennis Association said in a statement Thursday night.

“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. Due to the nature of this action, NYPD and medical personnel were needed in order to safely remove this individual from the stadium,” the statement continued.

According to the USTA, the NYPD took four protesters into custody.

Play resumed after the 49-minute incident.

Earlier this week, a spectator was ejected from a tennis match at the tournament after German player Alexander Zverev accused the man of quoting a phrase from Adolf Hitler's Nazi regime.

"He said the most famous Hitler phrase to me," Zverev told the umpire. "He just said the most famous Hitler phrase there is in this world. It's unacceptable. This is unbelievable."

The umpire immediately turned around to interrogate the crowd and ask the fan to identify himself.

"Put your hand up," Keothavong said. "Who said that? Who said that? Who said that? We are going to get him out."

Soon after, security officials were called in to remove the fan, who was apparently identified by spectators seated near him. The crowd cheered as the man was escorted out of the arena by security.

-ABC News' Morgan Winsor, Joshua Hoyoes and Darren Reynolds contributed to this story.