Six people protesting climate change came out of the crowd and stormed the 18th green while the leaders were lining up their putts on the final hole of regulation at the Travelers Championship, delaying the finish for about five minutes. 

The protesters waved smoke bombs that left white and red residue on the putting surface before Scottie Scheffler, Tom Kim and Akshay Bhatia finished their rounds. 

Some wore white T-shirts with the words "NO GOLF ON A DEAD PLANET" in black lettering on the front.

"I was scared for my life," Bhatia said. 

"I didn't even really know what was happening ... but thankfully the cops were there and kept us safe, because that's, you know, that's just weird stuff."

The PGA Tour issued a statement thanking the Cromwell Police Department "for their quick and decisive action" and noting that there was no damage to the 18th green that affected either the end of regulation or the playoff hole.

Scheffler, who was arrested during a traffic stop at the PGA Championship, also praised the officers.

"From my point of view, they got it taken care of pretty dang fast, and so we were very grateful for that," said Scheffler, the world's No.1 player, who beat Kim on the first hole of a sudden-death playoff.

"When something like that happens, you don't really know what's happening, so it can kind of rattle you a little bit.

"I felt like Tom and I both tried to calm each other down so we could give it our best shot there on 18."

Activist group Extinction Rebellion claimed responsibility for the protest. 

In a statement, the group blamed climate change for an electrical storm that injured two people at a home near the course on Saturday.

After the protesters were tackled by police and taken off, Scheffler left a potential 26-foot clincher from the fringe on the right edge of the cup, then tapped in for par. Kim, who trailed by one stroke heading into the final hole, sank a 10-foot birdie putt to tie Scheffler and force the playoff.

Kim said the protest took his mind off the pressure.

"It kind of slowed things down," he said. "It took the meaning of the putt away for a second. Because for the past 17 and a half holes all you're thinking about is golf, and suddenly when that happens your mind goes into a complete ... like, you're almost not even playing golf anymore. I thought it was a dream for a second."

The crowd surrounding the 18th green heckled the protesters by yelling profanities and cheered the police who intervened. After the players putted out in regulation, workers with leaf blowers came out to clean off the remaining powder.

"They left a lot of marks on the greens, which is not right for us players, especially when two guys are trying to win a golf tournament," Kim said.

"But I'm very grateful for the tour and the tour security for handling that really well and making us players feel a lot safer."