Alexandria City Public Schools will not immediately switch to three feet of separation inside classrooms, going against guidance from the federal government and the trend in Northern Virginia, where all other major school systems recently opted for that distance.

Alexandria officials announced Wednesday that the school district will stick with six feet of social distancing for the time being, citing worries that three feet would lead to high levels of quarantining. But the school district will switch to three feet for the in-person portion of its summer schooling and for regular fall instruction, which Superintendent Gregory C. Hutchings Jr. has promised will involve five days a week of on-campus learning.

Hutchings wrote in a statement to The Washington Post that Alexandria still plans to send more children back into classrooms before the end of the academic year, as he had previously suggested would happen. Since mid-March, the school system of 16,000 has returned about 5,400 children — about 35 percent of its student body — to two days a week of face-to-face instruction.

Hutchings also said in the statement that Alexandria is not going to expand the in-person learning program beyond two days a week before the end of the year. It is still unclear whether his school system will keep six feet all the way through the end of the academic year.

“At this time, we are using six feet of physical distance,” Hutchings wrote in a message to families Wednesday, “and are continuing to work to determine how the revised guidelines impact [Alexandria City Public Schools].”

The message spurred immediate outcry in some quarters of the community. On Facebook, parents swapped feelings of disappointment and anger. Some wrote that they had hoped to send their children — currently learning virtually — back for in-person school under the three-foot model and now expected they would be stuck online through the end of the semester.

“Dr. Hutchings’s inability to adopt the federal guidance is only going to continue the learning loss and further exacerbate equity issues,” said Ed Mills, who has two sons attending an Alexandria public school two days a week. “With this decision, neither equity nor science is being followed.”

The Centers for Disease Control and Prevention announced in late March that it was shifting its recommendation for appropriate classroom distancing from six to three feet. Just before that, Hutchings said at a board meeting that, if the CDC did change to three feet, his school system would probably bring more students back into classrooms after spring break. He noted there was significant parent demand to switch from all-virtual learning to the in-person program.

Spring break ended this week.

In an FAQ published online, Alexandria officials wrote that “operational considerations” drove the decision to stick with six feet. The FAQ notes that the CDC defines a “close contact” as taking place when someone comes within six feet of a coronavirus case and remains there for 15 minutes or longer within a 24-hour period.

People who qualify as close contacts have to quarantine for 14 days afterward, per CDC guidelines.

“Thus, classrooms with desks that are three feet apart will result in higher numbers of students who are required to quarantine when there is an identified case,” the FAQ states. “The higher number of students in the school buildings may also result in more individuals who are notified of exposure through contact tracing efforts which will significantly impact school operations and continuity of learning.”

These considerations have not stopped neighboring districts. Loudoun County Public Schools is switching to three feet and will begin offering four days a week of in-person instruction starting April 20. Fairfax County Public Schools, Virginia’s largest district, is also adopting three feet and will start sending students inside classrooms four days a week later this month.

And Arlington Public Schools is moving from six to three feet, too, allowing the school system to send more children back into classrooms before the end of the year. But the district does not plan to add more days of in-person schooling this semester, currently at two days a week, although children with special needs are coming into classrooms four days a week.

Some Alexandria parents said they were outraged to see their school system lag behind peer districts, apparently ignoring science and imperiling children.