A Baton Rouge police officer who claims he was injured during a protest after a deadly police shooting filed a lawsuit Monday against prominent Black Lives Matter activist DeRay Mckesson, who was arrested at the demonstration.

The unnamed officer's federal lawsuit says he was struck in the face by a piece of concrete or a "rock like substance" thrown at police during a July 9 protest over the death of Alton Sterling, a black man shot and killed during a scuffle with two white officers.

The suit doesn't accuse Mckesson of throwing anything at officers but claims he "incited the violence" on behalf of Black Lives Matter, which also is named as a defendant.

Mckesson "was in charge of the protests and he was seen and heard giving orders throughout the day and night of the protests," the suit says. "The protest turned into a riot."

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The suit, which seeks unspecified damages, says the officer lost teeth and had injuries to his jaw and brain.

Mckesson, who said he hasn't seen the suit and couldn't immediately comment on it, was among nearly 200 protesters arrested during the protests sparked by Sterling's fatal shooting July 5. He and other protesters have sued the city of Baton Rouge over their arrests, accusing police of using excessive force and violating their constitutional rights.

The officer suing Mckesson is identified only as "John Doe" in the suit, saying the anonymity is "for his protection." A separate court filing Monday cited the July 7 sniper attack that killed five Dallas police officers and the July 17 shooting that killed three law-enforcement officers in Baton Rouge as grounds for concealing the officer's identity.

The suit describes Black Lives Matter as a "national unincorporated association" and claims Mckesson is a "managing member" of it. Mckesson described himself as a leader of the Black Lives Matter movement.

"No organization started the movement," he said.

Dane Ciolino, a Loyola University law professor in New Orleans, said it's "really unusual" for the officer to sue under a pseudonym in a case of this kind. Ciolino also said it could be difficult for the officer's attorneys to prove that Mckesson or Black Lives Matter "aided and abetted" the alleged battery or somehow negligently allowed it to happen.

"Black Lives Matter is just a social movement. It's not an entity. I don't know how it could be liable," he said.

Donna Grodner, a Baton Rouge-based attorney for the officer, declined to elaborate on the suit's allegations. She said the officer is still being treated for his injuries.

Louisiana Gov. John Bel Edwards has defended the police response to the protests. The governor, a Democrat who comes from a family of sheriffs, also noted that a police officer had teeth knocked out by a rock during the protests.

It's unclear if that officer is the same one suing. Baton Rouge Police Sgt. Don Coppola, a department spokesman, declined to comment on the suit.

Mckesson, a Baltimore resident, was arrested July 9 near Baton Rouge police headquarters on a charge of obstructing a highway. East Baton Rouge Parish District Attorney Hillar Moore has said Mckesson is one of roughly 100 arrested protesters who will not be prosecuted by his office for the same charge.