The American Civil Liberties Union and other groups sued the Baton Rouge police on Wednesday, accusing law enforcement officials of violating the constitutional rights of people protesting the death of Alton Sterling.

Since Sterling was shot and killed by police officers last week, heated protests have erupted in Louisiana’s capital city as militarized police officers wearing riot gear have faced off against demonstrators in scenes broadcast widely online and on television. Roughly 200 protesters were arrested over a three-day period.

While police have defended their actions as necessary, protesters have questioned the tactics of law enforcement, and Amnesty International said the number of arrests in Baton Rouge “raises serious questions about proportionate response to peaceful protests.”

In the lawsuit filed Wednesday, the ACLU of Louisiana and other groups, including Black Youth Project 100, accuse police of responding “to peaceful acts of protest with unlawful restrictions on constitutionally protected activity and disproportionate deployment of militarized equipment and excessive force.”

The groups accuse law enforcement officials of physically and verbally abusing demonstrators, threatening protesters with pepper spray and using “objectively excessive force” during arrests.

“These actions have been designed to intimidate protesters and deter the continued exercise of First Amendment rights,” the lawsuit states.

The lawsuit, filed in the U.S. District Court for the Middle District of Louisiana, asks a judge to order the Baton Rouge police, the Louisiana State Police and other law enforcement agencies and public officials “from ordering individuals who are violating no law to refrain from gathering on public sidewalks.” It also asks a judge to mandate that any law enforcement officer responding to protests must wear visible personal identification and not use mace or pepper spray on demonstrators.

The Baton Rouge police and the state police did not immediately respond to requests for comment about the lawsuit.

Authorities in Louisiana have defended their response to protesters, saying that their gear — which evoked the chaos that unfolded on the streets of Ferguson, Mo., after a white officer shot a black teenager there in 2014 — was needed to protect police officers.

Louisiana Gov. John Bel Edwards (D) called the response “moderate,” while Louisiana State Police Col. Michael D. Edmonson said protesters in at least one instance had thrown bricks at police.

Police said their aggressive actions were prompted by a suspect in a burglary saying he and others stole several guns “to harm police officers,” Baton Rouge Police Chief Carl Dabadie Jr. said at a news conference Tuesday.

“This is the reason,” Dabadie said, “because we had credible threats against the lives of law enforcement in the city.”

The burglary occurred early Saturday morning, hours after officers lined the streets of Baton Rouge in riot gear. Police had not charged anyone involved in the burglary with anything related to threatening officers as of Wednesday afternoon, but a police spokesman said that it was an ongoing investigation and that other charges could be added.

The country has been on edge since a three-day period that saw Sterling shot and killed by two Baton Rouge police officers; police fatally shot a man in a traffic stop outside St. Paul, Minn., and 14 officers shot or injured by gunfire in Dallas, five of them fatally, during a peaceful protest over policing.

Officers in Baton Rouge said that they saw a gun in Sterling’s pocket and also say they saw him reach for the weapon, according to a police affidavit. The Justice Department has launched a federal investigation into the shooting, and the local prosecutor recused himself from any decision on criminal charges, citing his close professional relationship with the parents of one of the officers.

“We can’t bring Alton Sterling back, but at minimum, the police can stop blocking our right to protest in his name,” Marjorie Esman, executive director of the ACLU of Louisiana, said in a statement.

Demonstrations have continued in Minnesota, where protesters blocked part of an interstate Wednesday morning near downtown Minneapolis.

Police in Minnesota have arrested more than 100 people during protests there that authorities described as riots, where they say at least 21 officers were injured. So far, 48 people arrested during demonstrations over the weekend are facing criminal charges, according to the American Civil Liberties Union of Minnesota.

The group said charging these people for “nonviolent acts of civil disobedience … sends a chilling message to any individual who wants to engage in nonviolent protest in the future.”

The ACLU in Minnesota has not filed a lawsuit over the treatment of demonstrators, though the group says it is considering representing those demonstrators facing charges.

Further reading: 

Why police in Baton Rouge look like they’re dressed for war

As arrests mount in Baton Rouge, protesters question police tactics

‘I’m under arrest, y’all’: Black Lives Matter activist arrested, then released in Baton Rouge

‘Super-fishy’: Man who posted video of Alton Sterling killing claims he was targeted by vengeful police

Obama speaks at Dallas memorial and says ‘we ask police to do too much’