At least 19 students have been killed, with many reportedly female, after a suicide bomber detonated a device having entered an education centre in Kabul with other gunmen.
Police have said there was an explosion in the Afghan capital but have not confirmed who was responsible for the attack.
There was no immediate claim of responsibility for the blast which killed at least 19 people.
Harrowing images and footage from the scene showed rows of bodies laid out on the ground.
Hours after the explosion this morning, a student witness confirmed that girls made up the majority of the fatalities.
Many of those living in the western area where the blast occurred are Hazara, an ethnic mostly Shia minority targeted in past attacks launched by the ultra-radical Islamic State and others.
Local reports have said that a suicide bomber set off a device inside a school in Kors Kaj after a security guard was killed and eyewitnesses have said that the number of dead is high.
A teacher has reportedly said that four people ran into the school with shots being fired and one blew himself up.
There were around 150 students at the school who were there for entrance exams when the attack took place at 7.30am on Friday morning.
An unconfirmed list of dead has been shared on social media which shows there were a large number of females who were killed.
Police spokesperson Khalid Zadran said: "Attacking civilian targets proves the enemy's inhuman cruelty and lack of moral standards."
"The Kaj educational centre in the 13th district of Kabul city was attacked today, which was holding the entrance examination," he added.
"Unfortunately, preliminary information shows that 19 people lost their lives and 27 others were injured. Attacks on civilian targets that prove the brutality of the enemy are strongly condemned."
Due to the large numbers, bodies have been laid out at the educational centre, and there are reports that there are 11 so far in Alijanah hospital.
The official death toll is likely to rise. A hospital source said 23 people had been killed. A Taliban source said 33 people had been killed and that female students were among the casualties.
Ghulm Sadiq, a local resident, said he was at home when he heard a loud sound and went outside to see smoke rising from the education centre where he and neighbours rushed to help.
"My friends and I were able to move around 15 wounded and 9 dead bodies from the explosion site ... other bodies were lying under chairs and tables inside the classroom," he said.
Teenage students were among the 24 people killed in a 2020 attack claimed by Islamic State at an education centre in west Kabul.
Earlier this month a blast outside a mosque in the city of Herat in Afghanistan killed a high-profile pro-Taliban cleric as well as civilians.
"Mujib Rahman Ansari, with some of his guards and civilians, have been killed on their way toward the mosque," said Herat's police spokesperson Mahmood Rasoli after the attack on September 2.
Since taking over Afghanistan in August 2021, the Taliban have emphasised that they are securing the nation following decades of war, but recent months have seen a series of blasts.
