Protesters tried to interrupt the biggest U.S. energy conference, holding signs and using a microphone to shout "Climate Change is Genocide."

It's the first time in recent memory that environmental activists have made their presence felt at the CERAWeek by IHS Markit conference in Houston, an event that has armed uniformed city police officers stationed on several floors of the Hilton Americas hotel, who ask people entering the event to show their badges.

About half a dozen protesters managed to enter the downtown hotel before being quickly removed by police. They were carrying a sign that said, in part: "TELL THE TRUTH.. FRACKING DISPROPORTIONATELY AFFECTS COMMUNITIES OF COLOR." The incident occurred as U.S. Energy Secretary Rick Perry finished a luncheon speech at the conference. The protesters didn't interrupt the speech or make it to the room where the secretary was speaking.

"We're here to protest the extraction industry again," a 29-year-old protester named Danny, who refused to give his last name, said in an interview. "Climate change affects the global south, the places with black and brown people."

Meeting attendees Tuesday night heard from Bob Dudley, chief executive officer of London-based BP PLC, who said oil and natural gas producers are operating "in a world that is not on a sustainable path." He called for the industry to engage with policymakers around the world, "including those behind the Green New Deal."

Two weeks ago, oil executives gathered in London for IPWeek were confronted by environmental protesters who glued themselves to the doors of the venue.