Justin Bieber didn’t waste time addressing the mass shooting in Buffalo while performing there this weekend — right off the bat, he spoke on it … making for a moving night.

The singer was in town Saturday as part of his Justice Tour, taking the stage at KeyBank Center just hours after a man allegedly gunned down at least 10 individuals in what clearly appears to be a race-driven attack … but even amid the bloodbath, JB called for peace.

He posted a few videos showing him talking about the massacre at a few different points in the concert, including right before he took the stage … where he went into prayer with his team.

After that, Justin went on to perform to a packed house … full of people who were ecstatic to see him. It sounds like before he dove into any music, though, there too he took a moment to acknowledge the tragedy … and even called for a moment of silence from the crowd.

As you can hear, there were still a few people hooting and hollering even during this solemn period, and Justin kinda called ’em out in his caption — asking why they couldn’t respect it.

In any case, he wasn’t done addressing the shooting … at another point in his show, he stopped to discuss people’s obligation to continue to have conversations about racism … as a means of stamping out the hatred in some folks’ hearts and bringing them to the light.

He’s pretty eloquent in his comments here … and you can tell this is coming straight from the heart. The audience seemed to appreciate him being honest and poignant with them … but when he actually started singing, they lost it — per usual.

As you know, 18-year-old Payton Gendron was taken into custody Saturday on suspicion of first-degree murder, among other charges. He’s said to have livestreamed his rampage.