Pro-President Trump rally turns tense amid May Day march in downtown LA

DOWNTOWN LOS ANGELES (KABC) -- A rally held by supporters of President Donald Trump turned tense in downtown Los Angeles amid a massive May Day march on Monday.

Tensions rose as demonstrators wearing masks, who identified themselves as anti-fascists, came face-to-face with Trump supporters outside the Edward Roybal Federal Building.

One masked protester was arrested after burning an American flag and another man was arrested for throwing rocks at Trump supporters.

Officers formed a skirmish line between Trump supporters and demonstrators. Anyone who attempted to cross the skirmish line was detained.