Bike riders should watch out for “maliciously strung” wires across trails in the southeastern part of the state, according to Massachusetts Environmental Police.

The Department of Conservation and Recreation has received several reports of wire cable strung across trails, officials say. Wires have been discovered at F. Gilbert Hills State Forest in Foxborough, Franklin State Forest, Wrentham State Forest, and Freetown State Forest.

Officials have posted warning signs on the trails and on social media.

Authorities are asking anyone who sees something suspicious to call the environmental police at 1-800-632-8075 or the DCR park watch line at 1-866-759-2824.