A suicide bombing struck an educational center in a predominantly Shi'ite neighborhood of the Afghan capital on September 30, killing 20 people and wounding 27, a Taliban-appointed spokesman for the Kabul police chief said.
The explosion took place in the center of the Dashti Barchi neighborhood, which is populated by Hazaras, a mostly Shi'ite ethnic minority, in the morning hours, said spokesman Khalid Zadran. The explosion occurred in a classroom packed with students, he added.
Witnesses told RFE/RL that the assailant targeted the guard of the educational center before blowing himself up in the classroom.
Around 150 students were reportedly inside the building at the time of the blast.
The victims included high-school graduates who were taking a practice university entrance exam, Zadran said.
The Kaaj Higher Educational Center coaches mainly adult male and female students ahead of university entrance tests.
Witnesses quoted by AFP said most of the casualties were women.
Emergency, an Italian NGO that operates a hospital in Kabul, said it had received 22 patients, including 20 women, two of whom had died.
"The victims are all between 18 and 25 years old, and most of them were in the classroom to take an exam," Emergency said in a statement.
Zabihullah Haidari, a teacher at the center, told RFE/RL that a suicide attacker fired at guards in the gate: "The attacker also fired at people inside the educational center, and several people were killed in the shooting. Then he entered a class where students were taking an exam and blew up his explosives vest. Most of the victims were girls.”
The bombing is the latest incident in a stream of violence since the Taliban seized power last year in August. No one immediately claimed responsibility for the attack.
The extremist Islamic State group has in the past targeted the Hazara community, including in Dashti Barchi.
"Our teams have been dispatched to the site of the blast to find out more details," Abdul Nafi Takor, a Taliban-appointed spokesman for the Interior Ministry, said earlier.
The attack is a "shamefaced reminder of the ineptitude and utter failure of the Taliban, as de facto authorities, to protect the people of Afghanistan," Samira Hamidi of rights group Amnesty International said in a statement.
UN Special Rapporteur on Afghanistan Richard Bennett condemned the attack.
"Onslaught on education for Hazaras & Shiites must end. Stop attacks on Afghanistan's future, stop international crimes," he said on Twitter.