By Jonathan Allen

(Reuters) -The U.S. Department of Justice's Civil Rights Division has opened an investigation into whether the Memphis Police Department has an unconstitutional "pattern or practice" of using excessive force and racial discrimination, department officials announced on Thursday.

Earlier this year, the Justice Department agreed to join city officials and other agencies in a review of the Memphis Police Department after its officers fatally beat Tyre Nichols, a 29-year-old Black man, in the Tennessee city in January.

The federal investigation announced on Thursday is not tied to any specific incident, Assistant Attorney General Kristen Clarke said at a press conference, though she noted Nichols' "tragic death" in her remarks.

"City and police department leaders recognize the need to scrutinize the police department's practices to prevent such incidents from ever happening again," Clarke said. City and police officials had agreed to cooperate with the investigation, Clarke said.

Memphis Mayor Jim Strickland said in a statement that the city will be "a good partner" in the new investigation.

"However, I am disappointed that my request was not granted by the Department of Justice to discuss this step before a decision was made to move down this path," he said. "I hope the remainder of the process is more forthright and inclusive than it has been so far."

Memphis Police Chief C.J. Davis also pledged cooperation in a statement that criticized the conduct of the officers who beat Nichols while thanking other police officers "that continue to serve our city with integrity."

The Justice Department had received multiple reports of officers using excessive force, including when "faced with behavior they perceive to be insolent," Clarke said. Her office had also received reports that officers may use force against people who are already restrained or in police custody.

Federal investigators will also examine reports that officers may be involved in racial discrimination by disproportionately stopping Black people for minor violations in the majority-Black city, such as a broken tail light on their car.

Five officers who took part in the brutal beating of Nichols after stopping him in his car on Jan. 7 have been fired from the department and are being prosecuted for second-degree murder and other charges, to which they have pleaded not guilty. All five former officers are Black.

Videos of Nichols' deadly beating brought fresh outrage in a country where multiple police departments have repeatedly been found to use excessive force against Black people.

The Justice Department has investigated other police departments, including the Minneapolis Police Department following the 2020 murder of George Floyd, a Black man who was killed by a white police officer kneeling on his neck for more than nine minutes after Floyd had been handcuffed and said he couldn't breathe.

Last month, Minneapolis officials agreed to federal oversight of its police force by the Justice Department after it was found to have a practice of violating people's civil rights.

(Reporting by Jonathan Allen in New York; Editing by Aurora Ellis and Deepa Babington)