Story highlights Four agents rushed the stage after animal-rights protesters interrupted Clinton

Clinton looked to use the moment Thursday as an opportunity to take a jab at Trump's family

Washington (CNN) United States Secret Service agents rushed to protect Hillary Clinton at a Las Vegas rally Thursday after animal-rights protesters approached the Democratic presidential nominee.

The protesters held signs and chanted to protest the treatment of animals, prompting four agents to encircle Clinton, who never appeared to be in danger.

It's the first time agents from Clinton's detail have rushed the stage to protect her. Agents have run up to protect Republican nominee Donald Trump and Clinton's primary challenger, Bernie Sanders , at rallies earlier in the 2016 race.

Clinton looked to use the moment Thursday as an opportunity to take a jab at Donald Trump, whose sons are avid hunters.

"You keep talking. Apparently people are here to protest Trump because Trump and his kids have killed a lot of animals," Clinton said, smiling.