WASHINGTON (AP) — An inmate was killed after being beaten by another prisoner inside a high-security federal prison in Illinois, two people familiar with the matter told The Associated Press on Friday.

The Thursday death is the latest serious security issue for the federal Bureau of Prisons, which has been plagued by chronic violence, serious misconduct and persistent staffing shortages, and it once again raises questions about whether officials at the embattled Justice Department agency can adequately protect the safety of the more than 175,000 federal inmates across the U.S.

On Thursday, officers at another Bureau of Prisons facility — the Metropolitan Correctional Center in New York City, where wealthy financier Jeffrey Epstein killed himself in August — found a loaded handgun during a lockdown. And on Friday, federal prosecutors announced that four Bureau of Prisons officers had been indicted for lying about three inmate deaths at a prison in North Carolina in 2019.

The death at USP Thomson, a high-security federal penitentiary about 150 miles west of Chicago, comes just a week after Attorney General William Barr named a new director of the Bureau of Prisons.

In a statement, the agency said the 31-year-old inmate, Matthew Phillips, was found unresponsive at the prison on Monday. The facility houses more than 1,000 male inmates.

Phillips, who was serving a sentence of more than 7 years for distributing heroin and money laundering, suffered life-threatening injuries and was brought to a local hospital, where he died Thursday, the statement said.

The Bureau of Prisons did not disclose details of the circumstances leading to Phillips’ death, but two people familiar with the matter told the AP that Phillips was severely beaten. The people were not authorized to discuss the matter publicly and spoke on condition of anonymity.

The Bureau of Prisons said it notified the FBI and that no staff members or other inmates were injured.

Homicides in federal prisons are relatively rare. Federal statistics show 160 federal prisoners were killed between 2001 and 2016.