Provincial police are investigating dozens of bomb threats that were received across Ontario on Thursday that targeted schools, government offices, and several businesses. 

Authorities say the threats appear to be a hoax and no explosive devices were found.  

Police forces in Toronto, Montreal, Calgary, Ottawa, and Winnipeg, as well as RCMP detachments in B.C. and Manitoba  are also investigating similar threats that police are calling a crude extortion attempt.  Several U.S. cities also received threats that were investigated and dismissed.

Police say the threats were sent through email and demanded 20-thousand-dollars in the form of the digital currency bitcoin.

Authorities say each threat was taken seriously and investigated.

- With files from The Canadian Press