Massachusetts school buildings will remain closed to students for the rest of this school year, Gov. Charlie Baker announced Tuesday, a dramatic step aimed at preventing a rebound in COVID-19 transmission once the state emerges from the worst of the outbreak.

Baker also ordered non-emergency child care programs to remain closed until June 29.

K-12 schools had been closed until May 4 under Baker's most recent executive order, and Tuesday's announcement extends the physical shutdown through the end of the academic year. Remote learning will continue this spring, he said.

During a Tuesday press conference, Baker warned that COVID-19 is "an insidious and at times invisible virus."

"It's the right thing to do considering the facts on the ground associated with the COVID-19 pandemic. At this point in time, there is no authoritative guidance or advisory with respect to how to operate schools safely and how to get students to and from schools safely," he said. "We believe students therefore cannot safely return to school and avoid the risk of transmitting the virus to others."

The state is in the midst of the coronavirus surge, with confirmed cases likely to surpass 40,000 in the administration's Tuesday afternoon daily updated. More than 1,800 residents have already died as a result of the highly infectious virus, which public health experts warn can be spread even by those who are showing no symptoms.

On April 10, Baker signed a law allowing Education Commissioner Jeff Riley to vacate MCAS testing for the year and instructing the Department of Elementary and Secondary Education to modify or waive graduation requirements.

Several other governors have shuttered schools in their states into the summer, including New Hampshire Gov. Chris Sununu.