At least 40 people have been killed and dozens more injured in a bomb attack on girls leaving their school in a largely Shia Muslim neighbourhood in Kabul. Residents said they heard multiple blasts just as girls were leaving classes at the Sayed ul-Shuhada school in the Afghan capital to return home and break their Ramadan fast. Most of the victims appear to have been students. Saturday’s attack hit a joint high school for girls and boys, who study in three shifts, the second of which is for female students, Najiba Arian, a spokesperson for the education ministry, told Reuters. Images from the site of the attack showed bloodied backpacks and books lying across the street outside the school, as smoke rose over the neighbourhood. In the city’s hospitals, parents looked for their children on casualty lists, and some mourned beside bodies lined up along corridors. The attack was not claimed by any group. The Afghan president, Ashraf Ghani, blamed the Taliban, saying the group was “escalating their illegitimate war and violence”. The insurgent group said it had not carried out the bombing and in turn blamed Islamic State. Since the extremist group began operating in Afghanistan several years ago it has repeatedly targeted civilians from Afghanistan’s Shia minority in recent years, at schools, a gym and other places with no military links. An attack last year on a maternity hospital in the same district as the school, Dasht-e-Barchi, killed babies, new mothers and heavily pregnant patients. That attack was not claimed by any group, although the US also blamed Isis. The capital has been on high alert after months of targeted killings of journalists, activists and other civil society leaders, a campaign of assassinations that has pushed many into exile. The UN mission expressed its “deep revulsion” and the EU mission in Afghanistan condemned the school bomb as “a despicable act of terrorism”. “Targeting primarily students in a girls’ school, makes this an attack on the future of Afghanistan. On young people determined to improve their country,” the EU said in a statement on Twitter. Fears for the country’s future have intensified after the US president, Joe Biden, announced plans to withdraw all American troops by 11 September. The departure of the final 2,500 and 3,500 US forces still on the ground began a few days ago. The Taliban and the US last year signed an agreement to end their 20-year war, with Washington pulling out troops in return for security guarantees, and a promise the group would start peace talks with the Kabul government. Negotiations began last year but have largely stalled, as the resurgent Taliban, who now control or hold sway over half of Afghanistan, look to a time when Afghan government forces can no longer call in US air power and other help. The top US military officer said last Sunday that Afghan government forces faced an uncertain future and possibly some “bad possible outcomes” against Taliban insurgents as the withdrawal accelerates in the coming weeks.