Pokemon Go triggered a terrorism security alert - after dozens of players descended on a police station.
Officers were alarmed when a swarm of gamers turned up outside Leicestershire Police's HQ on Wednesday clutching their phones and taking photos.
But they were baffled when they were told the group said they were only there because they were searching for digital monsters as part of the popular game.
The force has now issued a warning to gamers to be mindful of their actions given the security threat levels around police stations and other civic buildings.
A spokesperson for Leicestershire Police said: "We are aware that there has been interest from young people around police stations in connection with Pokemon Go.
"We would like to remind people of the security threat level around public sector buildings and to consider their actions while in the vicinity of such buildings as police premises."
Pokemon Go players walk around searching the real world using satellite location to find creatures near them, and then use augmented reality to see and capture them.
It has been downloaded millions of times since its UK launch on Thursday days after it was released in the US, Australia and Japan.