A call about a man walking around Turtle Club Park in LaSalle with a knife and a pistol prompted a quick police response on Saturday.
Officers from the LaSalle Police Service quickly arrested a 21-year-old man and seized the weapons.
The pistol turned out to be a B.B. air pistol.
Police said no one was hurt.
The suspect faces criminal charges, but police did not specify what offence he was charged with.