School officials in Northern Virginia are urging students to stop playing a game that is reportedly scaring residents and leading to police reports of teens carrying weapons. Students have dismissed officials’ warnings, saying the “senior assassin” game is just “harmless fun” with water guns.

The assassins game is a social media trend that has become very popular among high schoolers in Fairfax and Loudoun counties. It consists of teens using water guns to spray other students, kicking them out of the game; oftentimes it’s played off campus.

According to a letter from Loudoun County Public Schools addressed to families, “some students are using water guns that are ‘look-alike’ or closely resemble real firearms.”

The school system said many bystanders have called the Loudoun County Sheriff’s Office with reports of people openly carrying guns, mistaking water guns for real weapons.

The letter states that they are deeply concerned that the game could cause a misunderstanding in public that could potentially endanger lives.

Officials reiterated that the senior assassin game goes against a school policy that prohibits weapons, including look-alike weapons, on school property.

NBC Washington first reported that Virginia schools were pushing back against the viral game on April 17. Students told reporters that the “fun” game had “no effect on the teachers or anything like that” and defended it as a harmless senior tradition.