Nashville Bomber Didn't Fire Shots Pre-Explosion, Federal Sources Say

Early reports of shots being fired in downtown Nashville before Anthony Quinn Warner blew his RV and himself to smithereens may be bogus -- because we've now learned there's no evidence he or anyone opened fire.

Federal law enforcement sources involved in the investigation and with direct knowledge tell TMZ ... yes, officers initially responded to the scene on Christmas morning after receiving reports of shots fired -- but since then, officials haven't been able to find anything to back that up.

We're told investigators have zero evidence to suggest Warner opened fire in or around the explosion site. Our sources say their initial theory was that Warner may have fired shots to get the cops to the downtown area where they would hear the recording from the RV of an impending explosion and clear the area so no one would be injured or killed in the blast.

There's another, more sinister theory ... that Warner wanted cops there to get close to the explosion, but officials now don't believe that. They say everything Warner did was to avoid loss of life, which is why he chose 6:30 AM on Xmas morning.

Now, our sources do say ammo was recovered at the scene, including exploded rounds that authorities say came from the RV ... however, they don't have markings of rounds fired from a gun. Authorities are convinced that ammo was in pristine condition until the explosion.

As for that loud bang prior to the blast, heard by the people who called 911 -- and we're told multiple people called -- our federal sources say they believe it could have been a recording of gunfire blaring from the RV, which would accomplish the same purpose of getting cops there to clear the area, but they just don't know for sure.

As we reported, there seems to be increasing evidence the AT&T building was Warner's main target.  Authorities think he may have been paranoid about 5G technology.