Police in Alameda said they are monitoring two unpermitted “beach takeover” gatherings promoted on social media for Robert W. Crown Memorial State Beach and plan to increase patrols to ensure public safety.

The events are advertised for Sunday and Tuesday, according to the Alameda Police Department. The East Bay Regional Park District owns Crown Beach, and park district police, supported by Alameda officers, will increase staffing during both days.

The department said the gatherings appear to target young people, raising concerns about the safety and supervision of minors. One event advertises an “assassin”-style game using water guns and water balloons.

While the activity may appear harmless, police said similar games in the past have led to unintended and dangerous situations.

Police urged parents and guardians to speak with their children and discourage them from attending unpermitted gatherings.