Joy and celebration turned into horror and carnage when a suicide bomber targeted a packed Afghan wedding hall, killing at least 63 people in the deadliest attack to rock Kabul in months, officials and witnesses said Sunday.

The blast, which took place late Saturday in west Kabul, came as Washington and the Taliban finalise a deal to reduce the US military presence in Afghanistan and hopefully build a roadmap to a ceasefire.

The groom, who only gave his name as Mirwais, recalled greeting smiling guests in the afternoon, before seeing their bodies being carried out hours later.

The attack "changed my happiness to sorrow", Mirwais told local TV station Tolo News.

"My family, my bride are in shock, they cannot even speak. My bride keeps fainting," he said. "I lost my brother, I lost my friends, I lost my relatives. I will never see happiness in my life again."

Interior ministry spokesman Nasrat Rahimi said at least 63 people had been killed and 182 injured. "Among the wounded are women and children," Rahimi said. Earlier he stated that the blast was caused by a suicide bomber.

Afghan weddings are epic and vibrant affairs, with hundreds or often thousands of guests celebrating for hours inside industrial-scale wedding halls where the men are usually segregated from the women and children.

"The wedding guests were dancing and celebrating the party when the blast happened," recounted Munir Ahmad, 23, who was seriously injured and whose cousin was among the dead.

"Following the explosion, there was total chaos. Everyone was screaming and crying for their loved ones," he told AFP from his bed in a local hospital, where he is being treated for shrapnel wounds.

In the aftermath, images from inside the hall showed blood-stained bodies on the ground along with pieces of flesh and torn clothes, hats, sandals and bottles of mineral water.

The wedding was believed to be a Shia gathering. Shia Muslims are frequently targeted in Sunni-majority Afghanistan, particularly by the so-called Islamic State group, which is also active in Kabul but did not immediately issue any claim of responsibility.

Wedding guest Mohammad Farhag told AFP he was in the women's section when he heard a huge blast in the men's area.

"Everyone ran outside shouting and crying," he said.

"For about 20 minutes the hall was full of smoke. Almost everyone in the men's section is either dead or wounded."

One guest who spoke to Tolo said some 1,200 people had been invited.

The attack sent a wave of grief through a city grimly accustomed to atrocities.

President Ashraf Ghani called the incident a "barbaric attack", while Afghanistan's chief executive Abdullah Abdullah described it as a "crime against humanity".

The attack underscores both the inadequacy of Afghanistan's security forces and the scale of the problem they face. While the police and army claim they prevent most bombings from ever happening, the fact remains that insurgents pull off horrific attacks with chilling regularity.

On July 28, at least 20 people were killed when attackers targeted Ghani's running mate Amrullah Saleh on the first official day of campaigning for presidential elections.

The incident showed how even amid tight security and known threats, insurgents can conduct brazen attacks.

The issue also goes to the heart of a prospective deal between the US and the Taliban that would see America begin to draw down its troop presence.

The deal relies on the Taliban providing guarantees they will stop jihadist groups such as Al-Qaeda and IS from using Afghanistan as a safe haven.

Saturday's attack suggests any such promise would be tough to keep.

The "Taliban cannot absolve themselves of blame, for they provide platform for terrorists," Ghani said.

Expectations are rising for a deal in which the US would start pulling its approximately 14,000 soldiers from Afghanistan, but few believe it will bring quick peace to Afghanistan.

Many Afghans fear the Taliban could return to some form of power, eroding hard-won rights for women in particular and leading to a spiralling civil war.

Insurgents have periodically struck Afghan weddings, which are seen as easy targets because they typically lack security precautions.