A suicide attack on an office of the Afghan Voice news agency and a neighbouring cultural centre in the capital Kabul killed dozens on Thursday, officials and witnesses said, with many of the victims students.
IS group claimed the attack, the group's Amaq news agency said in an online statement.
Interior Ministry deputy spokesman Nasrat Rahimi said at least 40 people had been killed and 30 wounded in the blast, the latest in a series to have hit media organizations in Kabul.
The attack occurred during a morning panel discussion at the centre, many of those attending students, witnesses said.
Sayed Abbas Hussaini, a journalist at the agency, said there appeared to have been more than one explosion during the attack, following an initial blast at the entrance to the compound. He said one reporter at the agency had been killed and one injured.
Photographs sent by witnesses showed what appeared to be serious damage at the site, in a heavily Shi'ite Muslim area in the west of the capital, and a number of dead and wounded on the ground.
Afghan Voice has Shi'ite links but there was no immediate claim of responsibility. Taliban spokesman Zabihullah Mujahid issued statement on Twitter denying involvement.
The attack, the latest in a series to hit Afghan media groups in recent years, follows an attack on a private television station in Kabul last month.
Backed by the heaviest U.S. air strikes since the height of the international combat mission in Afghanistan, Afghan forces have forced the Taliban back in many areas and prevented any major urban centre from falling into the hands of insurgents.
But high-profile attacks in the big cities have continued as militants have looked for other ways to make an impact and undermine confidence in security.
According to a report this month by media freedom group Reporters without Borders, Afghanistan is among the world's most dangerous countries for media workers with two journalists and five media assistants killed doing their jobs in 2017, before Thursday's attack.