(CNN) Three people were stabbed Thursday night at Chicago's Navy Pier and more than a dozen others were injured after being trampled when someone set off firecrackers, according to police.

Chicago Police spokesman Anthony Spicuzza said in a news release Friday morning that a fight broke out among a group of men at the fireworks display after someone displayed "gang signs."

A 14-year-old boy was stabbed in the arm and rib, according to Spicuzza, and a 15-year-old boy was stabbed in the armpit. Another man, 30, who was not involved with the fight, was stabbed in the face and arm but couldn't recall details of the stabbing and didn't see who was responsible.

All three are at local hospitals in stable condition, Spicuzza said.

Three people were stabbed and more than a dozen injured at Chicago's Navy Pier Thursday night.

Police initially believed that a fourth person, a 16-year-old boy, had been stabbed, he added, but it was later determined he punctured his leg after running into a table.

Read More