The singer and comedian got together in L.A. Sunday with a bunch of other women of color -- who have lost their own kids or relatives to violence ... be it from the police or at the hands of someone else. The purpose of the rally was to speak out against the killing of these children -- minors or adults, alike -- and to offer support to their grieving mothers.

We talked to Luenell about it, and she tells us the time to voice concern about this issue is more pressing than ever ... and they want the public and people in power, especially, to know #EnoughIsEnough, which also happens to be the official name for their viral campaign.

Now, while Luenell insists the issue of black children being murdered goes beyond law enforcement -- hers and Chaka's movement comes at a moment where, once again, we're seeing excessive violence being exacted upon men of color -- specifically, black men -- by cops and/or rogue vigilantes -- encounters that often lead to their deaths as a result.

Of course, we're referring to two recent cases of this in Ahmaud Arbery -- who was gunned down after a man and his son claim he fit the profile of a burglary suspect -- and Sean Reed, who live streamed his own death after cops gunned him down during a chase.

We've seen it before ... the list of black/brown people being killed by the authorities is long and well-documented. But, for Luenell and co., they're truly pissed and demanding structural change. Watch ... she's incredibly passionate about the cause and for good reason.