SALEM, Ore. (AP) — Under new COVID-19 metrics released Tuesday, students in most Oregon counties may not be able to return to their classrooms this fall, officials said.

In order for a school district to commence any form of in-person learning, the county must have 10 or fewer new cases per 100,000 residents over seven days, Gov. Kate Brown said during a news conference. In addition, the countywide and state test positivity rate must be 5% or less over the span of a week.

“Currently, in Oregon we are not where we need to be to safely reopen schools,” State Epidemiologist Dean Sidelinger said.

In the past week, case rates across Oregon were about 50 per 100,000 people, and the state's test positivity is approaching 5%.

“Our current case rates are higher than they need to be and higher than they were in other countries that began to reopen schools,” Sidelinger said. “But, we can suppress COVID-19 and return to levels where we reopen schools.”

Following Brown's announcement, Oregon’s largest school district, Portland Public Schools, said that it will have online classes only until at least Nov. 5.

In addition, Beaverton, Salem-Keizer, North Clackamas and Tigard-Tualatin districts also said they will be holding classes online.

Sidelinger said at this time there is only one county that meets the criteria for reopening school with in-person instruction, if the statewide positivity rate remains below 5%. But, there are some exceptions to the state metrics.

For kindergarten through grade three classrooms and rural school districts with fewer than 100 students — the metrics are looser.

In these cases, in-person instruction can begin if there are fewer than 30 cases per 100,000 and if COVID-19 is not actively spreading in the school. They must still have a positivity rate of 5% or less.

Based on these exceptions, 13 counties would be eligible for in-person learning — if the state positivity rate remains under 5% — Sidelinger said.

The new metrics for school reopening came as the Oregon Health Authority reported a record number of COVID-19 related deaths in a single day — 14. The previous record was nine.

Dr. Patrick Allen, the director of the Oregon Health Authority, described the increase in deaths as a “stark reminder of the work all Oregonians need to do to bring this pandemic under control.”

The total amount of confirmed and presumptive cases in the state since the start of the pandemic has surpassed 17,400. At least 303 people have died. Of the state’s total positive cases, more than 2,400 are among people younger than 20.

Health officials said younger students get the virus at lower rates, get less sick, and spread the virus less than older students and adults. However, if cases surge, schools that have reopened will be forced to close again.

On Monday, hundreds of Oregon teachers held a car caravan protest in Salem, calling for no in-person classes until counties report 14 days of no new COVID-19 cases. The nation’s largest teachers union on Tuesday authorized its members to strike if their schools plan to reopen without proper virus safety measures.

Students who do return to the classroom will be required to wear masks, along with teachers and school staff. Last week, the Oregon Department of Education announced that it was allocating $5 million to distribute face masks to school districts to meet the requirement.

“Closing schools in the spring was one of the most difficult decisions I have made in the pandemic,” Brown said. “As COVID-19 continues to impact both our urban and rural communities, it’s been clear that this school year will not look like any other school year.”