LOS ANGELES (AP) — Police were investigating allegations Monday that officers used excessive force when they dog-piled on a skateboarder who was punched during a weekend arrest recorded on video.

Ronald Weekley Jr., 20, claimed he suffered a broken nose, broken cheekbone and a concussion during the confrontation outside his home in the Venice neighborhood. His face appeared slightly bruised as he spoke with friends, supporters and journalists.

"We feel very strongly that his civil rights were violated," his father, Ronald Weekley, said in a telephone interview.

His son, who is black, may have been stopped because he was "an ethnic kid" in a predominantly white neighborhood, Ronald Weekley said.

Officers spotted the younger Weekley skateboarding in traffic, and he resisted when they tried to arrest him Saturday, police Cmdr. Andrew Smith said.

The officers called for backup, and Weekley was arrested on suspicion of using force to obstruct or resist police, Smith said.

A bystander caught some of the confrontation in a cellphone video. It shows four police apparently struggling with Weekley, who is under their bodies on a lawn. An officer is seen punching him once in the head.

The elder Weekley said his son went to a hospital before being taken to jail. He was released Monday.

Weekley and his son both said the police actions were unprovoked.

The son told KTLA-TV that he was skateboarding home and was nearly there when police grabbed him.

"I was being a good kid," he said. "I turned around to (find) two cops running directly at me and throwing me on the ground, putting my arms behind my back and tying my legs to my arms and telling me I was resisting arrest."

His father said his son stiffened his body as police tried to get hold of him and drag him to cement head first. Police didn't call for backup until his son was on the ground and had submitted, Weekley said.

"No witness will say that Ron was aggressive or forward or hit or struck or kicked anyone at any time," he added.

However, Smith said officers received minor scrapes and bruises.

"The video only shows a small portion of this incident," but it is consistent with the account given by the officers in their arrest report, Smith said.

"They documented everything that they did," he said. He declined to provide details because the incident is the subject of an LAPD internal investigation.

"Officers are authorized to use force to effect an arrest, to overcome resistance or to prevent escape," he said. "What happens during a traffic stop is predicated on the actions of the individual being stopped."

The son had three outstanding misdemeanor warrants, but his father said they were issued for violating curfew some years ago and weren't the reason for the police stop.

The officer in charge at the scene told Weekley that his son was stopped because he was riding his skateboard in the wrong direction, on the wrong side of the street, the father said.

"If that's an ordinance it's never been enforced, ever," Weekley said. "So we're left to conclude that the police didn't like the size of my son's nose, his ears, his tennis shoes, or something they were predisposed (to not like)," he said. "We live in a predominantly white community. The crime they're focused on is committed by black or brown (people). He was clearly an ethnic kid."