At least 40 people have been killed and 30 wounded in a suicide attack at a Shia cultural and religious organisation in a western area of the Afghan capital, Kabul.
The interior ministry told the BBC the suicide blast was followed by another two explosions in the area.
No-one has yet said they were behind the attack.
In recent months, so-called Islamic State has been carrying out attacks on Shia targets across the country.
The Taliban have issued a statement saying they were not involved.
Images on social media showed a number of bodies in a courtyard following the blast.
Deputy interior ministry spokesman Nasrat Rahimi told Agence France-Presse: "The target of the attack was the Tabayan cultural centre. A ceremony was being held to mark the 38th anniversary of the Soviet invasion in Afghanistan when the explosion went off."
A number of students were reportedly attending a discussion forum with media group members at the offices.
The head of Afghan Press, the media branch of the Shia organisation, told the BBC that so far dozens of bodies had been carried from the building and officials have reported dozens more being brought to hospitals.
In October, at least 39 people were killed in an attack on a mosque belonging to the Shia minority.