Video: Louisiana police criticised for treatment of protesters

East Baton Rouge district attorney Hillar Moore said his office had not made any decisions on charges against the protesters and that it would be done on a case-by-case basis.

"We're going to do as good job as we can, as quickly as we can, to try to go through the (police) reports as they come in," he said.

Mr Moore suggested that "first offenders" and people who may have just "stepped over a line" could have their cases resolved more quickly than those for protesters accused of carrying guns or injuring officers.

But with tensions rising since last week's killings of Alton Sterling in Baton Rouge and Philando Castile in Minnesota by white officers, and an attack on police by a black sniper in Dallas, Texas, that killed five officers, many have questioned whether the police response has been appropriate.

Kristy Carter, who has been protesting every night since Mr Sterling was killed, said officers outside the police station said it would not be a problem provided protesters did not cross barricades or stop traffic - but that in practice it was different.

"Yesterday evening we were standing here ... and they just started coming and attacking the crowd for no reason," Ms Carter said of the police. "They are telling us not to be violent, but they are being violent against us."

Jade Flint said police seemed to be getting more agitated as the Saturday evening protests went on.

"The job is to protect us while we are out here trying to protest for our rights. Not to agitate us and pick and grab people," she said.

Kira Marrero, 22, of New Orleans, was the first protester freed from Baton Rouge's jail on Sunday. She accused police of acting in an "inflammatory" manner and said an officer had pointed a rifle at her and other protesters before her arrest.

The American Civil Liberties Union of Louisiana said Baton Rouge police "used violent, militarised tactics on groups of people who have gathered peacefully in protest of Alton Sterling's killing".

Amnesty International questioned the high number of arrests during Saturday's protests and whether it was a "proportionate response to peaceful protests".

Louisiana authorities have said repeatedly that they have no problem with protesters and pointed out the number of rallies that have been co-ordinated with authorities and have gone off without problem.

In the first few days following Mr Sterling's death, police took a more reserved approach to enforcement, keeping a low profile as hundreds of people gathered outside the convenience store where he died.

Baton Rouge police chief Carl Dabadie said on Friday that his department was striving to avoid a "military-style response" to the protests.

But tensions ratcheted up and police arrested 200 demonstrators over a three-day period and took to the streets in riot gear, carrying rifles and driving armoured vehicles.

Governor John Bel Edwards said on Sunday he was "very proud" of how Louisiana's law enforcement agencies responded to the protests and did not believe police officers had been overly aggressive.

A Baton Rouge police spokesman said Monday that the arrests stemmed largely from people not obeying officers' commands.

"They had several opportunities to get out of the road, to disperse. They were ignored," said Sergeant Don Coppola, referring to one incident.

Asked why some officers were armed with high-powered rifles at protests, he said: "You don't really know what you're walking into. You want to have every precautionary means that you may need ... to disperse these crowds."

Mr Coppola said the department respected people's right to protest peacefully and people from outside Baton Rouge were largely responsible for confrontations at protests.

Police had confiscated three rifles, three shotguns and two pistols during protests, he said earlier.

One officer was hit by a projectile and injured in the weekend protests, authorities said.

On Monday, convenience store owner Abdullah Muflahi filed a lawsuit against Baton Rouge police claiming he was detained illegally after he recorded the confrontation between police and Mr Sterling on his mobile phone.

The writ says he was kept in the back of a police vehicle for four hours and detained at the Louisiana State Police headquarters for two hours while he was questioned.

A search warrant for surveillance video from the store said that, during the arrest, officers saw "the butt of a gun" in Mr Sterling's pocket and that he tried "to reach for the gun from his pocket".

The US Justice Department has opened a federal civil rights investigation into Mr Sterling's death.