Provincial achievement tests (PATs) at dozens of Calgary public schools are being delayed due to a network outage.

The Calgary Board of Education says the unexpected outage on the province's SuperNet affects more than 80 CBE schools, but only 25 were scheduled to write tests on Wednesday.

The school board says they will be delayed until May 20.

Officials say restoring the network is their top priority and they are working with the service provider to sort out the problem.

Information is being sent out to parents and students at the affected schools to advise of the change.

More information will be posted on the CBE website as it becomes available.