The clash, which officials blamed on quarrels between guests, erupted late Sunday in Deh Salah district in the once-tranquil province of Baghlan.
The province has recently been plagued by growing insecurity as the Taliban insurgency rapidly spreads north from its southern and eastern strongholds.
“As a result of the clashes, 20 people were killed and 10 others were wounded,” provincial police spokesman Jawed Basharat told AFP, adding that the incident appeared to be the result of a local dispute.
Armed men traded verbal barbs before the gunfight broke out and the victims were all male guests at the wedding aged between 14 and 60, said district police chief Gulistan Qusani.
“A local security official fired in the air after the verbal exchange heated up… and then both sides started trading fire,” Qusani told AFP, giving a higher death toll of 21.
Baghlan governor Sultan Mohammad Ebadi said an official delegation had been sent to the site — a Tajik-dominated area that is largely unaffected by the Taliban insurgency — to investigate and prevent any backlash from the relatives of the victims.
Expensive and lavish weddings have become common since the Taliban were toppled in 2001, in contrast to their time in power when musical revelry and dancing were banned.
But fatal gunfights and celebratory gunfire are woefully common at the ceremonies in a country battered by nearly 40 years of war.
The killings also highlight the lure of the gun culture in Afghanistan, especially across the insecurity-plagued countryside where owning firearms for personal safety is common among Afghan households.
– Growing insecurity –
Afghan soldiers mistakenly fired mortars at a wedding party in late December in the southern province of Helmand, killing 17 women and children.
Some witnesses said the army attack was triggered when wedding guests fired celebratory gunshots into the air as the bride was brought to the groom’s house.
In July 2012 a suicide bomber killed a prominent Afghan lawmaker and 16 other people at his daughter’s wedding party in the north of the country.
And in June 2011 gunmen stormed a wedding party in eastern Afghanistan, killing the groom and eight other people in an attack blamed on Taliban-linked insurgents.
The Afghan government conducted its first face-to-face talks with Taliban cadres on July 7 in a Pakistani hill station, aimed at ending the 14-year insurgency.
Afghan officials said Friday they would meet insurgents this week for a second round of talks, pledging to press for a ceasefire in negotiations likely to be held in China.
But despite the willingness to engage in talks there has been no let-up in militant attacks, which are taking a heavy toll on civilians.
A suicide bomber on Wednesday killed 19 people including women and children in a crowded market in the northern province of Faryab, as insurgents intensify their annual summer offensive launched in late April.
Almost 1,000 civilians were killed in the conflict during the first four months of this year, a sharp jump from the same period last year, according to the United Nations.
President Ashraf Ghani’s government has drawn criticism for failing to end growing insurgent attacks, which critics partly blame on political infighting and a protracted delay in appointing a candidate for the crucial post of defence minister.