Capitol Police said six of its officers were injured in the clash with protestors and one person was arrested for assaulting an officer.
According to the Associated Press, several Democratic lawmakers and candidates, including House Minority Leader Hakeem Jeffries, were inside the DNC building when the protests began.
Donning black shirts with the slogan “Cease Fire Now” the protesters said they planned to block the entrances and exits of the building to ensure the lawmakers would see their protest.
The police’s statement accused the nearly 150 protestors at the site were acting “illegally and violently.”
The protesters, however, told AP they were holding a non-violent vigil which was met with violence from the police.