The Saturday's blasts -- the deadliest in more than a year -- rocked the west Kabul district of Dasht-e-Barchi, a regular target of Sunni Islamist militants.
It comes as the United States military continues to pull out its last 2,500 troops from the violence-wracked country despite faltering peace efforts between the Taliban and Afghan government to end a decades-long war.
Describing Saturday's carnage, Interior Ministry spokesman Tareq Arian told reporters that a car bomb first detonated in front of the Sayed Al-Shuhada School, and when the students rushed out in panic two more devices exploded.
He said more than 100 people were wounded, adding that most of the victims were female students.
Residents were out shopping ahead of this week's Eid al-Fitr, which marks the end of Ramadan, the Muslim holy month of fasting.
On Sunday relatives began burying the dead at a hilltop site known as "Martyrs Cemetery".
No group has so far claimed the attack, but Afghan officials including President Ashraf Ghani blamed the Taliban.
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