Updated at 2:15 p.m.

All public and private schools in Massachusetts will remain closed through the end of this school year out of concerns for the safety of students and staff in the ongoing COVID-19 pandemic, Gov. Charlie Baker announced Tuesday.

Baker said there’s “no authoritative guidance” on how to re-open and operate schools safely or transport schoolchildren to and from school safely.

"We believe students therefore cannot safely return to school and avoid the risk of transmitting the virus to others," he said.

Baker’s decision will also keep childcare programs closed until June 29. All K-12 schools had been closed until May 4 under the governor's earlier order.

Baker said the state education department will increase efforts for remote learning.

“Closing actual school buildings for the year does not mean it’s time to start summer vacation early,” he said. “In the immediate future, the [education] department will launch a remote learning initiative.”

In the midst of a surge of COVID-19 infections, Massachusetts has now counted nearly 40,000 positive cases and the deaths of more than 1,800 people.

A new plan for remote learning for schoolchildren is expected Friday, said Education Commissioner Jeff Riley.

Riley did not offer specifics on his department’s new recommendations but stressed that remote learning is not the same as online learning.

“We've seen project-based learning taking place. We've seen work packets. We've seen different ways to reach kids,” he said. “What we are trying to do is make sure that we maximize all of our learning for our kids, recognizing that there are challenges.”

Asked about plans to reopen schools either this summer or in the fall, Riley said the most important factor remains the health and safety of the school community.

“What we've seen from other countries that have started the process of opening are things like temperature checking students, keeping desks six feet apart from students … and staggered schedules,” he said.

Baker and Riley both spoke about the “terrible and unprecedented” losses faced by students — not just of learning, but also of rituals like proms, sports and graduation ceremonies.