California backtracks on banning unmasked students from school campuses

California issued a new rule on Monday banning unmasked students from school campuses but then rescinded it just hours later.

The California Department of Health published its COVID-19 public health guidance for K-12 schools in the Golden State for the 2021-2022 school year, including a new mandate that said students "are required" to wear face masks indoors, unless they are exempt due to a medical condition, and "schools must exclude students from campus" if they refuse to do so. The guidance, which was initially published on Monday afternoon and took immediate effect, noted that schools "should offer alternative educational opportunities for students who are excluded from campus because they will not wear a face covering."

But later, officials backtracked on that rule. The California Department of Health took to Twitter on Monday evening to signal a change of direction, saying, "California’s school guidance will be clarified regarding masking enforcement, recognizing local schools’ experience in keeping students and educators safe while ensuring schools fully reopen for in-person instruction."

The guidance was ultimately revised, dropping the language about excluding unmasked students from classrooms statewide and instead allowing schools to decide how to deal with the issue.

"Consistent with guidance from the 2020-21 school year, schools must develop and implement local protocols to enforce the mask requirements," the guidance now states. "Additionally, schools should offer alternative educational opportunities for students who are excluded from campus because they will not wear a face covering."

The California Department of Health says the guidelines are "effective immediately and will be reviewed regularly." The department further noted that it is operating within the updated recommendations released Friday by the U.S. Centers for Disease Control and Prevention, which continues to advise schools to promote COVID-19 vaccination and implement indoor mask requirements and physical distancing for those who are not fully vaccinated. But the CDC's guidelines also state that schools "should not exclude students from in-person learning to keep a minimum distance requirement."

"Students benefit from in-person learning, and safely returning to in-person instruction in the fall 2021 is a priority," the CDC says.

Nevertheless, California's COVID-19 measures are among the strictest of any U.S. state. Education and health officials alike are concerned about the so-called delta variant, a highly contagious version of the novel coronavirus, with infections on the rise as the new academic year draws closer.

As of July 7, there were 1,085 confirmed cases of the delta variant in California -- a 71% rise from the previous week. Meanwhile, among the COVID-19 tests statewide that are genomically sequenced, the delta variant accounted for 43% on June 21 compared with just 5.8% on May 21, according to data from the California Department of Health.

Overall, California has reported more than 3.7 million confirmed cases of COVID-19 and over 63,000 deaths from the disease. More than 42.4 million doses of COVID-19 vaccines have been administered across to the state, which is home to some 39.5 million people, according to data from the California Department of Health.

ABC News' Marilyn Heck contributed to this report.