(Victoria Walker,Jenny Starrs/The Washington Post)

Anti-Trump protesters jeered and screamed at supporters of the president-elect outside the “DeploraBall” at the National Press Club on Thursday night, in one case throwing an object that struck a counterprotester in the head.

D.C. police closed the 1300 block of F Street NW to motor vehicles as hundreds of demonstrators filled the roadway. Some protesters raised their middle fingers and shouted obscenities and terms such as “racist” and Nazi” at those attending the celebratory ball on the eve of Trump’s inauguration.

A small group of protesters in hoods and black masks set a fire in the center of the street. Another fire was set in a trash can. A different group used a floodlight and stencil to project the phrases “Bragging about Grabbing a Woman’s Genitals” and “Impeach the Predatory President” onto the side of the Press Club building. Others inflated a 15-foot-tall white elephant with a banner attached that said “racism.”

Officers directed chemical spray at the crowd multiple times, starting around 9 p.m., after protesters began throwing trash at Trump supporters who were leaving the building.

During an earlier clash, a man was struck in the back of the head by a thrown object. About a half-dozen D.C. police officers surrounded him and escorted him behind police lines.

The DeploraBall drew attention on social media earlier this month, in part because several of the people who were said to be attending are known for being provocateurs, contributing to conspiracy-theory websites and sharing views with the alt-right, an extremist movement of mostly young men seeking a whites-only nation.

But the organizers say they are simply fans of the president-elect and in no way connected to the alt-right.

The ball’s name was inspired by Democratic presidential nominee Hillary Clinton’s description of some Trump supporters as “deplorables.” It was initially planned for the Clarendon Ballroom in Arlington. But that venue backed out.