Afghan officials say a suicide bomber targeted a gathering of Muslim religious scholars in Kabul, killing at least 40 people.
Interior ministry spokesman Najib Danish said the bomber sneaked into a large wedding hall where hundreds of scholars and clerics had gathered to mark the birthday of the Prophet Mohammed.
The people had gathered to celebrate the Prophet Muhammad's birthday, authorities said, and preliminary information shows the explosion may have been a suicide attack. That attack killed at least seven people and wounded 20.
A local affiliate of the IS group claimed a suicide bombing in June that targeted a meeting of the country's top religious body in the capital.
"There are a lot of casualties - I myself have counted 30 casualties", he told AFP on the condition of anonymity.
Wednesday has been declared a national day of mourning by the Afghan president, according to Hadid.
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Several articles have been written about the singer since her performance on the show. Pic on right was me before I just happened to sit down.
It is one of the deadliest attacks in Kabul in recent months.
While no militant group has yet taken responsibility, Monday's blast comes as Afghanistan's ongoing 17-year conflict tips in favor of the Taliban.
Shortly afterwards, a second explosion tore through a group of reporters who had gathered at the site of the first incident outside the headquarters of the Ministry of Urban Development.
United States envoy Zalmay Khalilzad expressed hopes in Kabul on Sunday that a peace deal to end the war could be struck before the Afghan presidential election, scheduled for April.
This month, Taliban militants for the first time attended an worldwide meeting, hosted by Russian Federation, to discuss the matter.
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.