EXCLUSIVE
Justin Bieber launched an all out egg assault on his neighbor's home tonight -- and the L.A. County Sheriff was called to the scene while the eggs were still flying ... this according to the alleged victim.
TMZ spoke to the neighbor who says he heard something banging against his house in Calabasas around 7:30 PM Thursday, and when he stepped on to a 2nd floor balcony ... he says he saw down below Justin hurling eggs at his front door.
According to the neighbor ... Bieber started aiming for him once he stepped onto the balcony and yelled, "What the Hell are you doing?"
Justin and the neighbor -- who've had previous run-ins -- then got into a verbal dispute while JB allegedly continued tossing a few more eggs at the house ... before retreating back to his home.
The neighbor immediately called the Sheriff's Department -- and believes his house was bombed with no less than 20 eggs.
Law enforcement sources confirm deputies responded, and took an incident report from the neighbor.
Calls to Bieber's reps were not immediately returned.
