Some bodies had been double-counted when they were being taken to hospital from the blast site following the attack on Wednesday, the ministry said.

The injury toll was revised to 56 from 67.

Most of the victims were students preparing for university entrance exams in a classroom at the Mawoud Academy in an area of west Kabul where many members of the city’s mainly Shi’ite Hazara community live.

Investigators said the bomber entered the centre from a rear entrance and made his way into a classroom where more than 100 students had gathered.

Their funerals were due to take place on Thursday.

There has been no claim of responsibility but the Taliban denied carrying it out.

The Hazara have often been targeted by the hardline daesh militant group.

The blast was the latest in a wave of attacks that have killed hundreds of civilians, soldiers and policemen over recent days.