Investigators from the Bureau of Prisons, the Justice Department’s inspector general’s office and other U.S. law enforcement agencies visited the Metropolitan Detention Center (MDC) in Brooklyn, the Bureau of Prisons said in a statement to The Associated Press .

The law enforcement activity was “designed to achieve our overall goal of maintaining a safe environment for both staff and individuals incarcerated at MDC Brooklyn,” the agency said. Prison officials declined to provide details about the activity on the morning of October 28.

The prison has faced increasing scrutiny over poor conditions, rampant violence and multiple deaths, and the Justice Department and the Bureau of Prisons have been working to fix the problems and hold offenders accountable.

Last month, federal prosecutors charged nine inmates in connection with a series of attacks between April and August at MDC — New York’s only federal prison.

Several federal agents have gathered at MDC Brooklyn, the federal prison holding Sean “Diddy” Combs. Photo: Gardiner Anderson/New York Daily News.

The charges detail serious safety and security issues at the prison, after two inmates were stabbed to death and another was stabbed in the spine with a homemade ice pick. A corrections officer was also charged with shooting at a car during an illegal chase.

Earlier this month, an inmate was charged in connection with a murder-for-hire plot that led to the death of a 28-year-old woman last December outside a city nightclub. Prosecutors said the inmate used a contraband cellphone to orchestrate the plot from behind bars while awaiting sentencing for directing another shooting years earlier.

The criminal charges shed light on the violence and disorder that has plagued the prison, which houses about 1,200 people including Combs and Sam Bankman-Fried, founder of the collapsed cryptocurrency exchange FTX. The total number of inmates is down from more than 1,600 in January.

In a statement on October 28, the Bureau of Prisons said the operation in Brooklyn was pre-planned and there was “no credible threat.”

The agency said it would not provide further details about what investigators are doing until the operation is complete “in order to maintain the safety and security of all personnel inside the facility, as well as the integrity of the operation.”

The facility, located in an industrial area on the Brooklyn waterfront, is primarily used to hold people awaiting trial in federal court in Manhattan or Brooklyn after arrest. Other inmates are there to serve short sentences after being convicted.

Inmates at the Brooklyn jail have long complained of rampant violence, poor conditions, severe staffing shortages, and smuggling of drugs and other contraband, some facilitated by staff. At the same time, they say they are routinely locked down and barred from leaving their cells for visits, phone calls, showers, or exercise.