Falmouth police are warning the public about a man who has exposed himself and masturbated near women who were hiking at a popular local preserve.

Falmouth police, in a statement posted Wednesday afternoon on the department’s Facebook page, said the man exposed himself twice on trails at the Blackstrap Hill Preserve off Blackstrap Road.

Police said the first incident was reported on Sept. 15 and the second incident occurred Tuesday.

The suspect is described as a white man, 20 to 30 years old, about 6 feet tall and 180 pounds, according to police.

The Falmouth Land Trust says the Blackstrap Hill Community Forest and Preserve consists of two parcels covering nearly 600 acres and is the largest block of contiguous protected open space in Falmouth. The property is almost entirely wooded, with the west branch of the Piscataqua River running along the northeastern edge.

Falmouth police are reminding people who use trails and open space areas “to remain vigilant of their surroundings and to immediately report signs of suspicious behavior” at 781-2300.