Black Metal Band Faces Backlash For Throwing Pig's Head in Crowd

A black metal band might've gone too far with their latest gimmick ... drawing the ire of fans on social media after tossing around a severed pig head at a recent show.

Martyrdom played a gig at the White Swan in Houston, TX on Friday -- when one of the band members made the bonehead move of bringing a severed pig's head to the show ... and later hurling it around the room, some of which was caught on video.

Check out the vid -- pigs really do fly in this case, with the head soaring from the middle of a circle and into the crowd amid screams and blaring music. Someone also took a still of the head ... and it's a pretty terrifying-looking thing to have thrown in anyone's direction.

Now, if you're wondering how social media reacted ... the answer's pretty emphatically NOT good. The boys in the band are getting tons of backlash for bringing the head -- with some people making "Lord of the Flies" references ... and others playing the animal cruelty card.

Martyrdom must've realized they messed up because they've since released an apology -- saying their stunt got out of hand and they didn't mean to offend anyone. They went on to apologize to any "vegans, Muslims or other minority groups" they offended as well as anyone who was "harmed" during the act. At this point, it's unclear if the swine caused any injuries.

The group also apologized specifically to the venue, and the sound operator ... though it's unclear how he might've been affected by the set. Worth noting ... the band has done this before -- and the act of throwing pig heads is kind of a pastime of metal bands, period.