Anti-Trump protest groups promised aggressive and potentially violent demonstrations earlier this week, and they delivered on their promise Thursday evening when several demonstrators clashed with Washington's Metropolitan Police Department on the street while the pro-Trump 'DeploraBall' party was taking place inside the National Press Club.

Man struck in head by protester

According to the Washington Post, protesters were pepper-sprayed by police after hurling garbage and other objects at Trump supporters as they arrived and departed the celebratory event on 14th Street.

Fox News reports that at least one Trump supporter sustained injuries after allegedly being struck in the back of the head with a flagpole by an anti-Trump protester.

Tensions came to a boil shortly before 9 p.m., as hundreds of demonstrators confronted Trump supporters with signs and chants of "Nazi scum." Police in riot gear dispensed a chemical spray into the mob after they began hurling garbage at Deploraball attendees.

The Washington Times reports that protesters wearing hoods and black masks set fires in the streets, while CNN reports other protesters hurled eggs at the National Press Club building. Hugh Carew, of the Metropolitan Police Department, announced that at least one arrest had been made.

Scott Ryan Charney, 34, was charged with conspiracy to commit assault.

More mayhem expected tomorrow

Based on the statements made by some of the protesters, Thursday night's violence was just a preview of things to come.

CNN interviewed one of the protesters, a 26-year-old woman named Sarko Sarkodie, who stated, "I'm out here tonight because I want to be part of the resistance efforts happening this week, and the resistance that'll be happening the next four years."

The DeploraBall event was organized by high-profile Donald Trump supporters, and some of the attendees included Geraldo Rivera, Sean Hannity, Sheriff David Clarke and Martin Shkreli. The event's name was inspired by Hillary Clinton's description of Trump supporters as a "basket of deplorables."