(Newser) – What was supposed to be a joyous occasion turned into a bloodbath last night as two armed groups at an Afghan wedding got into a gunfight, killing 21 people—including two teen boys—and wounding at least eight others, an Afghan official says, per CNN. The shooters, most of whom were guests at the wedding in Baghlan province, were believed to be members of illegal local militias, not the Taliban or al-Qaeda, NBC News reports. Although CNN says the cause of the fight was "unclear," the police chief of the Dih Salah district of Baghlan tells the AP it appears the fight broke out after a relative of a provincial police officer was killed during the celebration for a local mullah's son, for which 400 or so people had gathered at a private house.

Meanwhile, the police chief tells the Guardian that " a local security official fired in the air after the verbal exchange heated up … and then both sides started trading fire." The paper notes that "celebratory gunfire" and fatal shootouts are "woefully common" in the region. The paper cites a December wedding in which 17 women and children were killed after Afghan army soldiers heard such celebratory gunfire and blasted mortars at the wedding party by mistake. The AP notes that Baghlan and other northern Afghan provinces have been riddled with insurgent attacks since the 2001 US-led invasion overthrew the Taliban, but it adds that local feuds and other criminal activity still proliferate under the cover of war. (The Taliban attacked the Afghan Parliament just last month.)

