MILWAUKEE (CBS 58) -- Four men were arrested after Milwaukee police say they were firing off gunshots from a boat in the outer harbor, on the water east of the Summerfest Amphitheater. 

According to police, officers responded to the area just after 5 p.m. on Friday, Oct. 23. 

Police say officers heard gunshots and were also approached by people who reported what they heard and saw. 

Officers, according to police, located the vessel with four suspects on board: a 26-year-old man, a 23-year-old man, and two 24-year-old men. A firearm was recovered.

All four suspects were arrested, and criminal charges were referred to the Milwaukee County District Attorney's Office.