A suicide bombing at an education centre in Afghanistan's capital killed 24 people including teenage students and wounded dozens more.
The interior ministry says security guards had identified a bomber who detonated explosives in the street outside the Kawsar-e Danish centre in Kabul on Saturday.
Most of the victims were students aged between 15 and 26, according to the health ministry. Fifty-seven were injured in the attack, the interior ministry says.
A Taliban spokesman on Twitter denied responsibility for the attack, which came at a sensitive time as teams representing the insurgents and the government meet in Qatar to seek a peace deal.
Islamic State claimed responsibility in a statement on Telegram, without providing evidence.
Family members gathered at a nearby hospital, searching for missing loved ones among bags containing the remains of those killed, laid out on the hospital floor, while outside orderlies wheeled injured patients on stretchers for treatment, a Reuters witness said.
The attack, which was condemned by NATO and the Afghan government, took place in an area of west Kabul that is home to many from the country's Shia community, a religious minority in Afghanistan targeted in the past by groups such as Islamic State.
Dozens of students died in the same area of Kabul in an attack on another education centre in 2018.
The US Special Envoy for Afghanistan Zalmay Khalilzad early on Sunday on Twitter called again for an immediate reduction in violence and an acceleration in the peace process, citing rising violence in the country in recent weeks including a finding by the human rights commission that an Afghan government air strike had killed 12 children.
Earlier on Saturday a roadside bomb killed nine people in eastern Afghanistan after it struck a minivan full of civilians, a local official said.
Ghazni province police said a second roadside bomb killed two policemen after it struck their vehicle as it made its way to the victims of the first explosion.
No one immediately claimed responsibility for the attacks, which wounded several others.
Australian Associated Press