Kansas City ? Police say three men have been shot to death in an apartment building in Kansas City. Five people have been taken into custody for questioning.

Kansas City Police Officer Darin Snapp tells the Kansas City Star that it was a “very violent encounter” that he describes as “almost execution-style.”

Snapp says police got a call around 7:15 p.m. from a resident in the building who reported hearing gunshots. When officers arrived, the apartment door was open and there were no signs of a break-in. Snapp says the attackers may have been let into the apartment.

The five people were taken into custody when police saw them running out the back door of the building. Snapp describes them as persons of interest, not suspects.