The so-called Islamic State militant group has said it was behind a suicide attack on a wedding in Kabul which Afghan authorities said killed at least 63 people and injured 182 others.
IS said one of its fighters blew himself up at a "large gathering" in Kabul while others "detonated a parked explosives-laden vehicle" when security forces arrived, in a statement posted on the Telegram messaging app.
The attack came as the Taliban and the United States are trying to negotiate an agreement on the withdrawal of US forces in exchange for a Taliban commitment on security and peace talks with Afghanistan's US-backed government.
The Taliban denied responsibility and condemned the blast at a west Kabul wedding hall, in a minority Shia neighbourhood, packed with people celebrating a marriage.
Nasrat Rahimi, an interior ministry spokesman, said women and children were among the casualties.
The blast follows a bomb attack on a mosque in Pakistan on Friday that killed a brother of Taliban leader Haibatullah Akhundzada.
No one claimed responsibility for that blast, which killed four people and wounded about 20.
Pictures on social media from the scene of the Kabul blast showed bodies strewn amid overturned table and chairs at the wedding hall, with dark bloodstains on the carpet.
Wedding halls have become a big business in Kabul as the Afghan economy slowly picks up and families spend more on celebrations.
Big, brightly lit halls now line some suburban streets of the city.
At least 40 people were killed in an explosion at a wedding hall in Kabul in November.
IS militants also operate in Afghanistan and have carried out attacks in towns and cities, some aimed at members of the Shia minority.
There has been no let-up in fighting and bomb attacks in Afghanistan over recent months despite the talks between the US and the Taliban since late last year.
The Taliban have been fighting to expel foreign forces and re-establish an Islamic state since they were ousted in October 2001, weeks after the 11 September attacks in the US.
Both US negotiators and the Taliban have reported progress after eight rounds of talks since late last year.
Taliban officials said yesterday the killing of the brother of their leader in a bomb attack in Pakistan would not derail the talks with the US aimed at securing their long-cherished goal of getting foreign troops out.
Taliban negotiators were preparing for what they hope will be a final round of talks, the officials said.
No date for a new round has been set.
US President Donald Trump has made no secret of his desire for a US pullout from Afghanistan and an end to America's longest war.
Just completed a very good meeting on Afghanistan. Many on the opposite side of this 19 year war, and us, are looking to make a deal - if possible!— Donald J. Trump (@realDonaldTrump) August 16, 2019
Top US national security advisers briefed Mr Trump on Friday on the negotiations.
The Afghan government has not been involved in the talks because the militants refuse to deal with an administration they see as a US puppet.
There are concerns among Afghan officials and US national security aides about the talks with fears Afghanistan could plunge into a new civil war that could see a return of Taliban rule and international militants finding a sanctuary.
Under the expected deal, the Taliban, in exchange for a US commitment on a withdrawal, would guarantee Afghanistan would not be a sanctuary for militants to plot new attacks, both sides have said.
The Taliban are also expected to promise to open power-sharing talks with the government and agree to a ceasefire.
Around 14,000 US troops remain in Afghanistan, training and advising Afghan security forces and conducting counter-insurgency operations.