CLEVELAND — A few dozen demonstrators holding banners printed with a red-brick design formed a human wall Wednesday to mock Donald Trump's plan to seal off the Mexican border as another day of protests got underway in the streets outside the Republican convention. Demonstrators in downtown's Public Square held up a sign saying "Wall Off Trump" before marching off to the convention arena. There were no signs of trouble, unlike Tuesday, when skirmishes broke out among demonstrators and police used their bicycles to keep them apart. A threatened flag-burning later Wednesday had potential to fuel already bubbling tensions outside the Republican National Convention. Cleveland Police Chief Calvin Williams said that he spent three hours Tuesday evening riding with bicycle officers on patrol and that he waded into one confrontation because he's "still a police officer." Williams said he plans to show up wherever there are "issues" during the convention. Officers on Tuesday used bicycles to wall off intersections and for the first time during the convention ordered demonstrators to disperse under the threat of arrest. "We don't care who it is.