BUFFALO, N.Y. (WIVB) – Graphic video shows Buffalo police shoving a protester, who tumbles backward and strikes his head on the pavement outside of City Hall.

The footage, captured by WBFO, shows one officer bending down to check on the man, who is lying on his back and appears to be bleeding from his ear, but another officer pulls him up and the police march around the injured man.

Police originally said that “one person was injured when he tripped and fell.” It’s not clear whether they were referring to the incident that was caught on camera.

Later in the night, Buffalo Police Department Capt. Jeff Rinaldo said that internal affairs has opened an investigation into the incident, and that the investigation was ordered by the commissioner of police.

Buffalo Police Commissioner Byron Lockwood has ordered both officers involved in the incident suspended immediately without pay.

State police medics aided the injured man, and a source says that he suffered a laceration and a possible concussion. He’s reported to be in ECMC in stable condition.

Erie County Executive Mark Poloncarz tweeted about the incident on Thursday evening, saying:

Police say four people were arrested on disorderly conduct charges for blocking traffic in the area. A fifth was arrested and charged with disorderly conduct during a skirmish involving protesters. Police originally said that one person was injured when he tripped and fell.

Other than the arrests and the injury, the protest was peaceful.

The city’s curfew is in effect until 5 a.m. It’s in effect every day from 8 p.m. to 5 a.m. through and including Sunday.