CBS 58—Brown Deer Police responded to their first Pokemon-related call Monday.

The "Pokemon Go" app is the most downloaded in iTunes. The GPS-based app allows users to walk around and catch Pokemon, but it’s also causing people to break laws and ordinances.

An anonymous tip about trespassers led police to Brown Deer United Church of Christ and two sixteen year old boys.

“In dealing with them they said that they were playing the Pokemon go game and were trying to catch characters which they believed were on the roof of the church,” said Officer Brad Caddock with the Brown Deer Police Department.

Police say it’s important to use common sense and keep one eye on the real world while you play.

“Reports of it, not here in Brown Deer, where people have abandoned  their vehicles with the car doors open, left the car running as they’re trying to capture these characters within the game,” Caddock said.

And Caddock hopes those more serious Pokemon mishaps don't happen here, and that  local gamers remember that catching Pokemon isn't worth a trip to the pokey.

“We often times get to deal with several weird things, and this probably rates right up there with some of the weirder, more comical things we deal with,” Caddock said.

The two teens were let off with a warning, that Pokemon can go on private property but they cannot.

Police also say parents should talk to their kids to make sure they don’t wander off while playing the game.