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.