Ontario Provincial Police say they are investigating multiple bomb threats in Northern Ontario.

The threats were directed to multiple schools in several school boards in Northwestern and Northeastern Ontario, which demanded payment.

No evidence of devices were found but as a precaution the majority of targeted schools have been closed while the investigation continues.

The OPP is encouraging parents to contact their schools or school boards for more information.

In addition to officers in the communities affected, members of the Cyber Investigation Team are now part of the investigation.

Students at schools in the Coseil scholaire de district catholique des Aurora boréales have been sent home following a threat made overnight.

In a social media post the board says it received a dubious message with threats.

Ten schools are affected including at Franco-Supérieur and ÉSC de La Vérendrye in Thunder Bay, École Catholique des Étoiles-du-Nord in Red Lake, École Catholique de L'enfant-Jésus in Dryden and Ecole Immaculée Conception in Ignace.

Parents are asked to pick up their children as the schools are now closed.

A spokesperson with the board says police are investigating the threats.