It all happened near Fiserv Forum, where just minutes prior to the chaos, Giannis Antetokounmpo had helped earn Milwaukee an NBA title with a victory over the Suns.

Multiple cameras captured the terrifying images from the streets surrounding the arena ... and in footage from WISN12 News' broadcast -- you can see just how horrifying the situation was.

Gunfire erupted loudly and repeatedly near hundreds of fans who were celebrating the victory ... and it all grew so intense, people could be seen sprinting from the area in fear.

Milwaukee Police have not given specific details surrounding the shots yet -- but officials did say in a statement Wednesday that 3 people were injured in shootings shortly after the Bucks won it all.

According to cops, a 19-year-old woman, a 32-year-old man, and a 22-year-old man all suffered non-life-threatening injuries.

Police added they've launched an investigation into it all.

Just before the gunfire broke out ... the scene was epic in Milwaukee -- with more than 60,000 fans cramming into areas near the stadium to watch the game and then celebrate the win afterward.

Some were seen climbing on street poles after the victory ... while others were caught on camera leaping into the Milwaukee River.