Climate protesters interrupted the US Open semi-final between Coco Gauff and Karolina Muchova for 49 minutes, with one gluing their feet to the floor.

Security escorted three out but it took longer to the remove the fourth.

The United States Tennis Association (USTA) said all four were in New York Police Department (NYPD) custody.

"The fourth protester affixed their bare feet to the floor of the seating bowl," the USTA said in a statement.

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

Play stopped at 20:05 local time in New York when American sixth seed Gauff was leading 6-4 1-0 when the incident happened.

While the players waited, Czech 10th seed Muchova received some medical treatment and Gauff practised serves.

Gauff, who went on to win 6-4 7-5 after a thrilling end to the match, told ESPN she had predicted there might be an interruption at Flushing Meadows this weekend.

"The crazy thing is I told myself there would be a climate change protest in the final - I didn't think it would be in the semi-final," she said.

"When it happened I told the court ref it was a protest.

"I felt something would happen because it happened at the French Open and it happened at Wimbledon."

Members of the crowd voiced their frustration at the stoppage and directed chants of "kick them out" towards the protesters.

Eventually, the players were instructed to leave court and head to the locker room as security staff and NYPD officers tried to resolve the situation.

"Two of them [protesters] were removed, they quietly left without further protest," US Open tournament director Stacey Allaster told ESPN.

"When security got there, they found that one of the protesters had physically glued themselves in their bare feet to the cement floor."

The protesters were wearing T-shirts with the logo of the Extinction Rebellion protest group and bearing the slogan 'End Fossil Fuels'.

Earlier this year, Just Stop Oil protesters interrupted play at Wimbledon by throwing orange-coloured confetti and jigsaw pieces on to court 18.