Two Antifa agitators were arrested Thursday night during a vigil to remember slain conservative activist Charlie Kirk.

People gathered in Boston Common and lit candles to honor Kirk, who was shot and killed last week on a Utah college campus.

A group of protesters was separated from the vigil by barriers. Police officers were present on the ground and atop the statehouse, Boston.com reports.

President Donald Trump said this week that he would designate the radical left-wing group Antifa a “terrorist organization.”

Counter-protesters confronted people attending a prayer vigil for Charlie Kirk in Boston.  (Reuters/Lauren Owens Lambert     )

He plugged in the device again and began shouting at the attendees of the vigil, police said. When confronted by officers, he began calling them names such as “Nazis,” “fascists” and “White supremacists,” the police report said. He continued to ignore commands and was placed under arrest, police said.

The underage suspect was allegedly seen shouting obscenities at the vigil crowd and was escorted out of the area.

While leaving, he punched someone wearing a “Make America Great Again” hat on the arm, police said.

Counter-protesters rally at a prayer vigil for Charlie Kirk in Boston. Two were arrested Thursday during a vigil for the conservative activist.  (Reuters/Lauren Owens Lambert     )

While searching him, authorities found a hunting knife, according to the police report.