The Will County Sheriff’s Office “strongly discourages” youths participating in a prank known as “senior assassin” after responding to an incident several blocks from a Joliet school.

On Friday, there was increased police present at Crystal Lawns Elementary School as deputies investigated an incident several blocks from the building, according to a statement on Facebook from the sheriff’s office.

Plainfield School District 202 officials told the community the incident was “determined to be a senior prank and there is no threat to the building,” the sheriff’s office said.

The sheriff’s office said a prank known as “senior assassin,” typically involves students being assigned another “student target” and attempting to “eliminate them” with the use of water guns, while avoiding being tagged themselves, police said.

“While often intended as a fun tradition, the way the game is played can create serious safety concerns,” the sheriff’s office said.

The sheriff’s office said the prank could lead to the following:

• Neighbors seeing suspicious behavior, such as people hiding or following people, and calling 911.

• High school participants may use water guns or other versions of airsoft guns that could look real.

• If police are called to investigate suspicious behavior the “situation could escalate quickly.”

The sheriff’s office “strongly discourages” participation “senior assassin” pranks.

“We would like to ask parents to speak with their teenagers about making correct, smart and safe choices,” the sheriff’s office said.