The Public School System says two of the new cases relate to the Chacha Oceanview Middle School and Francisco M. Sablan Middle School.
The Commonwealth Healthcare Corp has yet to state where the third case was identified.
Effective from today, Governor Ralph Torres has directed the temporary closure of all public and private schools and colleges to mitigate against community spread.
As contact tracing in relation to the cases swung into action, Mr Torres has reassured the public that the CNMI would be able to contain the outbreak.
"I want to personally assure the educational community, staff, parents, families, and students that we will do everything as a government to protect the Commonwealth as we have successfully done throughout the course of the pandemic.
"We have the tools in place to contain this," said Torres.
The three new cases bring the total Covid-19 count for the CNMI to 294 individuals since March 28, 2020.
In consultation with the Healthcare Corp and the Governor's Covid-19 Task Force, the recently identified infected individuals have been quarantined and are being actively monitored.
The Corp's Communicable Disease Investigation/Inspection team has already initiated contact tracing for the most immediate contacts of the newly confirmed cases, and this effort will continue until all probable cases are identified and tested.