The OPP in Huntsville are investigating a suspicious letter sent to local media that makes non-specific threats against beaches in the Muskoka region.
A group calling itself the Islamic Revolutionary Force says it will destroy beaches and the tourist industry from Toronto to North Bay..
This comes a few weeks after broken glass was found on the beaches of Bracebridge and Gravenhurst.
Police have not found a link between the hazardous litter and the suspicious letter.
Bracebridge Mayor Graydon Smith says they're taking this seriously and while police investigate, public works staff are out on the beaches daily keeping an eye out for anything suspicious.