There was a tense moment on the campaign trail for Sen. Bernie Sanders on Monday.
Secret Service agents stepped in to protect the Democratic presidential candidate when animal rights protesters tried to rush the stage at a rally in Oakland, California.
The agents took down at least four protesters before they made it onstage. One appeared to hit a protester with his baton.
The animal rights group Direct Action Everywhere says it was their members who tried rushing the stage during Monday's rally.
But the incident didn't appear to rattle Sanders.
"We don't get intimidated easily," Sanders told the crowd as the Secret Service led the protesters away.
Sanders even joined a packed house at Oracle Arena in Oakland later that day for Game 7 of the NBA Conference Finals.
This is at least the second time a protester has tried to jump onstage to confront a presidential hopeful this campaign season.
In March, a protester rushed the stage at a Donald Trump rally in Ohio, but agents grabbed him before he got too far.
This video includes images from Getty Images and clips from NBC, KNTV and ABC.