THE BRONX - An investigation into a past homicide ended with gunfire and three arrests.

According to police, officers approached a group of men near Bronx Park East and Allerton Avenue, but they took off running.

The suspects allegedly dropped one gun and pulled out another. Investigators say that's when cops opened fire.

Authorities remained on the scene hours later. Sources say they were examining a shell casing left on the ground.

Three men were arrested and two firearms were recovered. No one was hurt.