As Mass. reports 702 new confirmed coronavirus cases, Boston Public Schools delay return to school for grades pre-kindergarten to 3

People waiting in line for coronavirus testing in Brookline this week.Erin Clark/Globe Staff

The number of confirmed coronavirus cases in Massachusetts climbed by 702, bringing the total to 139,353, state officials said Friday, as Boston Public Schools announced that it was delaying the return to classrooms for students in prekindergarten through third grade by at least a week.

The state also said the percentage of people tested for COVID-19 who are positive leaped from 3.9 percent to 5.8 percent, its highest position in many weeks and more than three times the rate at the beginning of September.

Boston officials decided those prekindergarten through third grade students would begin in-person learning no sooner than Oct. 29 after the citywide infection rate ticked up to 4.4 percent, the School Department said in a statement.

"While we are confident that the preparations we have made in our school buildings make it a safe environment for in-person learning for a limited number of students, we are taking the necessary time before we bring back the next wave of students,” Mayor Martin J. Walsh said in the statement.

The city announced earlier this month that the date for prekindergarten and kindergarten would push back from Oct. 15 to Oct. 22 after the citywide infection rate reached 4.1 percent.

City officials and the Boston Teachers Union had previously agreed that a 4 percent rate would trigger a full school closure. On Wednesday, a Suffolk Superior Court judge denied the union’s request for an injunction that would have allowed educators to choose whether to work remotely while positivity rates exceed 4 percent.

Boston schools began the year Sept. 21 with remote-only instruction and brought back the first students for in-person learning Oct. 1. Those included only students with high needs, such as severe disabilities, limited English background, and those facing homelessness or involvement with child protective services.

Under the plan announced Friday, high-needs students will be able to expand from two classroom days per week to four days, beginning Thursday, the School Department said.

The Boston Public Health Commission gave the go-ahead for the expansion after reviewing schools' health and safety protocols, officials said. The rest of the district’s calendar for phasing in classroom teaching remains unchanged for the time being.

Superintendent Brenda Cassellius said the changes provide a balance of safety and learning opportunities.

“This new announcement allows for us to continue providing enriching teaching and supports for our students in buildings while continuing to offer innovative online learning for families who have selected remote for their students,” Cassellius said in the statement.

Across the state, many thousands are being tested for the virus. Friday’s data showed that 14,962 more people had been tested, bringing the total to more than 2.48 million. The number of administered tests climbed to more than 5.01 million since the state’s public health emergency was declared in March. The state also reported that new antibody tests had been completed for 321 people, bringing that total to 123,893.

The death toll from confirmed virus cases in Massachusetts rose by 30 to 9,482, the Department of Public Health reported.

The seven-day average of positive tests per total tests administered was at 1.4 percent. The lowest observed figure for that metric — a number watched closely by state officials — is 0.8 percent.

Meanwhile, the three-day average of hospitalized coronavirus patients held steady at 505. The lowest that metric has been is 302.

The number of hospitals using surge capacity was two, and the three-day average of deaths from confirmed cases was 18; the lowest that number has been is nine.