Federal authorities investigating anti-Obama Nazi message on Massachusetts golf course.

The U.S. Secret Service and the FBI are investigating an incident at a Lakeville, Massachusetts golf course, in which vandals etched “I” above a swastika and “Obama” on the green. The Boston Herald reports that vandals used the heels of their shoes or cleats to scrape the message into the grass:

“We investigate these cases thoroughly,” said Steven Ricciardi, special agent in charge of the Secret Service’s Boston office. Authorities say the incident “likely constitutes a hate crime, whether the culprits meant it as a prank or not.”