The incident -- which happened at around 8:44 p.m. at a local park in North Charleston -- was captured on video sent to ABC News 4 from a viewer ... showing as kids were playing in a game, dozens of gunshots rang out from a nearby parking lot.

According to the North Charleston Police Department, witnesses said the gunfire happened shortly after a large group of teenagers got into a fistfight in the area. Cops say the teens opened fire on each other following the physical altercation, but fled the area before officers arrived.

Police say three cars were hit by bullets during the incident ... but somehow, no one was injured.

As for the baseball game, you can see in video, coaches and players were horrified by it all -- with kids hitting the ground in an attempt to avoid any stray bullets.

A spokesperson for the NCPD said Tuesday morning the gunfire had nothing to do with the game ... adding that the mayor of North Charleston was "appalled by what he heard and saw."

The spokesperson said an investigation into the incident is underway ... explaining, "We will leave no stone unturned in bringing these suspects to justice."

Cops also said they're looking into ways they can make parks and playgrounds in the area safer -- and are providing resources to the kids who were affected by the terrifying incident.