“Limited group gathering will be afforded to the extent practical to facilitate commissary, laundry, showers, telephone, and [computer] access,” the Bureau’s announcement said. “During this time, to the extent practicable, inmates should still have access to programs and services that are offered under normal operating procedures, such as mental health treatment and education.”

A tally released Tuesday by the federal prison system reported 29 inmates and 30 staff have tested positive for Covid-19. Union groups have asserted the numbers are higher than the official count. One federal prisoner has died from the virus.

Criminal justice reform backers, including some lawmakers, have been pressing for immediate release of older inmates and those at particular risk due to preexisting health conditions.

“We hope you will institute aggressive measures to release medically compromised, elderly and pregnant prisoners, as well as universal testing in BOP facilities — to protect everyone … Urgent action is required because lives depend on it,” wrote Judiciary Committee Chairman Jerry Nadler (D-N.Y.) and Rep. Karen Bass (D-Calif.), chair of the Crime, Terrorism and Homeland Security subcommittee.

Attorney General William Barr has ordered a review of the prison population for inmates who could be sent to home confinement without jeopardizing public safety.

While Barr proposed increasing the number of inmates on home confinement, he said last week that many inmates are likely safer in prison than outside. Any releases under the new policy seem likely to be at least a week away because Barr has said he wants such prisoners to be quarantined before being sent home.

"We also have to provide that anyone who is released to home confinement is quarantined before they go out, for 14 days to ensure that we're not putting people out in the community who have it,” he said.

There are about 167,000 federal prisoners spread between federal facilities and private or locally run jails, with about 10,000 of them older than 60, according to Barr. The vast majority of the U.S. prison population is under state and local authority.

One of the massive virus-response bills passed by Congress last week gives the Justice Department more authority to release federal prisoners early if Barr declares that an emergency is interfering with prison operation. The Justice Department has not responded to questions about whether Barr has yet issued such a declaration.

One criminal justice reform advocate expressed disappointment in the lockdown, saying it is likely to aggravate problems related to the virus, not ameliorate them.