Funerals have begun for victims of a series of blasts near a secondary school in Kabul on Saturday, now known to have killed more than 50 people.

The explosions took place as students were leaving the building. Most of the victims were girls, officials said.

No-one has admitted carrying out the attack in Dasht-e-Barchi - an area often hit by Sunni Islamist militants.

Afghan government officials blamed Taliban militants for the attack, but the group denied any involvement.

Nobel Prize winner and activist Malala Yousafzai - who was shot in the head by the Taliban in 2012 - posted about the "horrendous attack" on Twitter.

"My heart is with the Kabul school victims' families," she wrote.