Dozens of people were wounded in the attack, health ministry spokesman says, which targeted top clerics in Kabul, gathered at a wedding hall to mark Prophet Muhammad's birthday.
Over 50 people were killed in a suicide bomb attack on a meeting of top clerics in Kabul on Tuesday, officials said, in one of the deadliest attacks to strike the Afghan capital in months.
Dozens of people were wounded in the blast, health ministry spokesman Wahid Majroh said, which targeted a gathering of religious leaders, including members of the Ulema Council, at a wedding hall to mark the Prophet Muhammad's birthday.
"The suicide bomber detonated himself inside the hall during a ceremony by religious scholars," Kabul police spokesman Basir Mujahid said.
Interior ministry spokesman Najib Danish said the number of dead or wounded was "more than 50" so far.
A manager of Uranus Wedding Palace, which also hosts political and religious functions, told AFP news agency a suicide bomber blew himself up in the middle of the gathering of religious scholars.
"There are a lot of casualties –– I myself have counted 30 casualties," he told AFP on the condition of anonymity.
Afghan Taliban denied involvement and condemned the attack, in a statement.
Afghanistan's Tolo News TV, quoting witnesses, said at least 1,000 people were inside the wedding hall when a suicide bomber detonated explosives.
TRT World's Sultan Faizy has more from Kabul.
No claim of responsibility
There was no immediate claim of responsibility for the blast, but Daesh has claimed most recent suicide attacks in Kabul, which has become the deadliest place in the country for civilians.
Afghan President Ashraf Ghani condemned the bombing, calling it "an attack on Islamic values and followers of the Prophet Muhammad," and declaring Wednesday a day of mourning.
"It is an attack on humanity," Ghani said.
Pakistan's Prime Minister Imran Khan also condemned the bombing and expressed condolences to the victims.
It is the bloodiest assault in the Afghan capital since a twin bomb attack on a wrestling club in September that killed at least 26 people.
Last month's parliamentary elections sparked a wave of deadly violence across the country, with hundreds killed or wounded in poll-related attacks.
It is not the first time that religious scholars have been targeted by militants in the deeply religious country.
In June a suicide bomber struck near a gathering of clerics in Kabul, about an hour after the group had proclaimed such attacks a sin.
Taliban intensifies pressure
The latest attack comes as the Taliban intensifies pressure on Afghan security forces, even as the international community ramps up efforts to convince the group to engage in peace talks.
US envoy Zalmay Khalilzad expressed hopes in Kabul on Sunday that a peace deal to end the 17-year war could be struck before the Afghan presidential election, scheduled for April.
His comments underscore an apparent increasing sense of urgency in the White House and among American diplomats for a peace deal to be done quickly.