FLORISSANT, Mo. (AP) — A suburban St. Louis detective has been suspended after a video appears to show a police SUV knocking a man to the ground before an officer jumps on top of him and hits him at least twice while handcuffing him.

Florissant Police Chief Tim Fagan said this weekend he was “deeply concerned” after seeing the video and has asked St. Louis County police and the FBI to investigate.

The 20-year-old man was treated for an ankle injury and was released. He and another man who was with him face drug and resisting arrest charges. Fagan said no weapons were found on either man or in their car.

On Sunday night, protesters blocked a road in front of the heavily-barricaded Florissant police department, holding a “die-in” on the street, in which the participants lay face down with their hands behind their backs, the St. Louis Post-Dispatch reported. No violence was reported.

Fagan vowed to be transparent so the public could be assured that the police department is doing what it can to protect them.

“I'm upset,” Fagan said about the video. “Obviously there's such tension right now in the community certainly as it relates to law enforcement. Anytime you see a member of your department involved in a resisting (arrest) you never look good ... to see a citizen struck by a police vehicle is concerning."

The detective is a 9-year veteran of the force and had no previous incidents that required an outside investigation, Fagan said.

The arrest occurred about 11:30 p.m. Tuesday in Dellwood. A resident's doorbell camera shows the police SUV hitting a man who was running past the home. The officer jumps on top of the man, who is screaming, and hits him before handcuffing him.

Fagan said the officer, whose name has not been released, was on duty because of civil unrest in the area during protests over the death of George Floyd in Minneapolis. The arrest occurred a day after four St. Louis police officers were shot and a retired St. Louis police captain was fatally shot during a violent night in the city.

Two other officers who were with the detective but are not seen on the video participating in the arrest are on leave pending the investigation, Fagan said.

The officers were pursuing the vehicle the two men were in because it had been nearby the evening of June 1 when a shot was fired across from the Florissant police station. Officers saw the vehicle Tuesday night in a parking lot with its lights off, Fagan said. The two men eventually jumped from the car and tried to flee on foot.

Fagan said he was aware that an arrest that involved injuries was made Tuesday night but he did not see the video until Saturday. He said an internal investigation will determine what caused that delay.

“We want the same answers that the public does,” he said.

St. Louis County Prosecuting Attorney Wesley Bell said a special prosecutor has been appointed in the case because a relative of one of his staffers was at the scene. St. Charles County Prosecuting Attorney Tim Lohmar's office is investigating with the help of St. Louis County police and the FBI.

U.S. Attorney Jeff Jensen issued a statement saying his office, the Civil Rights Division at the Department of Justice and the FBI are aware of the case and will review the evidence to determine what federal response is warranted.