A threatening letter from a group claiming to have destroyed beaches in Muskoka is now under investigation by the OPP.

The letter, allegedly written by a group called the Islamic Revolutionary Force, claims that several beaches were destroyed through the winter with snowmobiles.

“Yes, we have destroyed your beaches over the winter months with snowmobiles, easily and effectively making them unsafe and all but unusable,” the letter reads.

“We started with the Muskokas and other tourist destination.”

The letter claims that northern Ontario towns were an easy target for the group. It also states that more beaches between North Bay and Toronto will be destroyed.

The letter, which was first received by the Huntsville Forester, was then passed along to the towns of Bracebridge and Gravenhurst on Friday. Neither community was specifically named in the letter.

A spokesperson for both towns confirms with CTV News that there doesn’t appear to be damage caused by snowmobiles on any of their beaches.

In late April, broken glass, sewing needles and fishing hooks were found at Bracebridge Bay Park and Kirby’s Beach Park. The beaches were closed for several days, and the OPP was notified.

At this point, there is no correlation between the hazardous materials found in Bracebridge and the letter.

Gravenhurst also found broken glass at one of its beaches last month, and alerted the public about it. However, a spokesperson says finding glass after the spring thaw isn’t unusual, adding that the incident appears to be unrelated.

The rejection of Islam and a following of “the Great Satan” are highlighted as the motives behind the alleged destruction.

The letter also says “the IRF fights against the disgraceful and unjust religious persecution of Muslim Canadians and of Islamic peoples throughout the world.”

The letter has since been handed over to police. An OPP spokesperson tells CTV News that they are taking the threat very seriously and are now investigating.