CLEVELAND — The tensest exchange yet between the police and protesters at the Republican National Convention unfolded Wednesday afternoon with officers arresting several people after some of them tried to burn a United States flag near the site of the convention.  Just before 4 p.m., demonstrators spread word that someone would be burning a flag near the entrance to the Quicken Loans Arena, where the convention is being held. Soon after, a group of people, some claiming to be members of the Revolutionary Communist Party, USA., came to the area with a flag and someone began to light it on fire, several witnesses said.  As the flag’s edge began to singe, the police called out for assistance and officers swarmed through the area on foot, on bicycle and on horses. One officer clutched the flag while others began handcuffing demonstrators.  Dozens of demonstrators erected a cloth wall outside the Republican National Convention in symbolic protest of Donald J. Trump’s controversial proposal to build a wall between the U.S. and Mexico.  Nearby, officers on bicycles and horses pushed the crowd back and tried to calm the scene.  Matt Harkins, 22, a reporter for WVBR, a student-run radio station at Cornell University, who witnessed the first moments of the encounter, said the flag was “singeing.” He added that soon after a mist filled the air.  “I almost passed out,” Mr. Harkins, of Erie, Pa., said. “It was putrid. It smelled sour.”  Later, officers shouted “move, move, move” while using their bicycles to push back people in the crowd and form a barrier around those getting arrested. Minutes after the arrests, the Cleveland Police Department said in a Twitter message, “Firefighters extinguished and took the flag that protesters attempted to destroy.”  Firefighters extinguished and took the flag that protesters attempted to destroy pic.twitter.com/8y63HApqnP  The department said two officers were assaulted and suffered minor injuries.  Those who were arrested were wearing black T-shirts with red and orange lettering that read, “Revolution nothing less!” As they were led away in handcuffs. s  Calvin D. Williams, the chief of the Cleveland Police Department, said on Wednesday evening that about 18 people were arrested and that two had been charged with felonies and 15 with misdemeanors. The charges included failure to disperse, inciting violence and assault. The two police officers had “minor bumps and bruises,” the chief said.  Burning a flag is permitted by law, Chief Williams said, and the officers intervened with fire extinguishers because the person who set fire to the flag “lit himself on fire” and then, while trying to fend off the police, “got a couple of other people lit on fire.”  Chief Williams said that he did not know of anyone who had been treated for burns.  The arrests followed a mostly peaceful day of protests, with police standing nearby but not interfering much with the demonstrations. In the morning, Code Pink, an antiwar group led by women, staged a “beauty pageant” to voice their opposition to Mr. Trump’s candidacy and accuse him of unfairly stereotyping various groups.  Later, a coalition of groups built a “wall” made of posters around the entrance of the Quicken Loans Arena to criticize Mr. Trump’s plan to build a wall across the border with Mexico. Activists, who locked arms and formed a long line, shouted “wall off Trump,” “undocumented, unafraid” and “there ain’t no debate, Trump equals hate.”
Police officers called for reinforcements, who swarmed an area near the Quicken Loans Arena and arrested about 18 people who were trying to burn a flag.