German police say they've arrested an 18-year-old man who was wanted for evading a prison sentence after he ventured out to play the newly launched "Pokemon Go" smartphone game with friends.

Police in Trier, on Germany's western border, said the group's "peculiar behavior" as they played the game in the city on Friday prompted officers to check their papers.

The 18-year-old initially gave a false identity but police quickly established that there was an arrest warrant out for him. He was detained and is now serving a six-month prison sentence he had previously avoided serving — police wouldn't specify for what.

The app was officially rolled out in Germany earlier this week.

The game has sparked a frenzy of players wandering around U.S. cities hunting for "pocket monsters" to fight.