Department of Defense “contractors” landed on a Mexican beach and accidentally declared it United States territory in a bizarre incident on Monday.

A group of unidentified men hammered in six signs on Nov. 17, declaring that a beach near Playa Bagdad in Northeast Mexico was “Department of Defense property” and had been classified as a “restricted area” by “the commander.” The area is roughly twelve miles south of the U.S.-Mexico border.

Heavily armed Mexican Navy personnel came to investigate the scene and discovered that the men had landed in Mexico by mistake and intended to plant the signs in South Texas. The situation was resolved without violence, and the Mexican Navy removed the signs. Pictures and videos of the incident circulated on social media over the following days.