See how Pokémon Go works, and why everyone's so crazy about it. (Video: Jhaan Elker/The Washington Post)

Some Pokemon Go players ended up caught by armed robbers in their quest to catch 'em all, according to a Missouri police department.

The augmented-reality game, which was released last week to so much fanfare that its servers were regularly overloaded, allows players to catch cute digital critters via a smartphone app by exploring real-world locations.

But some criminals — no doubt fans of the villainous Team Rocket — appear to have used the game's mechanics for evil: In a Facebook post Sunday, police in O'Fallon, Mo., said four people used the app to target victims in armed robberies in the St. Louis area in recent days.

"It is believed these suspects targeted their victims through the Pokemon Go smart phone application," according to the social media post. Specifically, the robbers appear to have watched the game's map for a particular player-triggered feature that attracts Pokemon to a specific location for a limited time — to figure out when potential victims were likely to be in isolated areas such as parking lots.

Police caught four suspects after responding to a call about a robbery 2 a.m. Sunday and recovered a handgun, according to the Facebook page. The O'Fallon Police Department did not immediately respond to a request for details.

In an unrelated incident, a teenager in Wyoming discovered a body while exploring a river bank in search of water-type Pokemon last week, according to the local news outlet KTVQ.

Some players have also reported injuring themselves because they were walking around with their eyes locked on their smartphone screens — basically ignoring the real world for the Pokemon-filled version in the palm of their hand.