CHICAGO (WGN-TV) — Chicago school leaders will cancel classes for a third straight day after failing to reach an agreement Thursday with the teachers union over remote learning and other COVID-19 safety protocols in the nation’s third-largest school district.

An official statement by CPS read: “Classes are canceled for all CPS students tomorrow, Friday, January 7. However, a small number of schools may be able to offer in-person activities for students. Please do not plan to send your child to school unless you hear otherwise from your child’s principal.”

The Chicago Teachers Union, which voted to revert to online instruction, told teachers to stay home Wednesday during the latest COVID-19 surge while both sides negotiate, prompting district officials to cancel classes two days after students returned from winter break. Chicago Public Schools, like most other districts, has rejected retuning to remote learning, saying it worsened racial inequities and was detrimental to academic performance, mental health and attendance. District officials insist schools can safely remain open with protocols in place.

The Associated Press contributed to this report.