The death toll in multiple blasts outside a girls' school in Kabul on Saturday afternoon rose to 63, relatives of victims and sources said, adding that more than 150 others were wounded in the incident.

But the Ministry of Interior Affairs said that 52 people were killed and 100 more were wounded in the blasts.

The incident started with a car bomb explosion outside Sayed -ul- Shuhada High School in the west of Kabul on Saturday afternoon and was followed by two rocket attacks as sources explained.

The Ministry of Interior says three blasts happened near the school: a car bomb attack and two IED blasts that were planted in the area.

The death toll in the blasts might increase, Tariq Arian, a spokesman for the Interior Ministry, said on Sunday. 

No group or individual have so far claimed responsibility for the blasts while the Taliban denied involvement in the attack by condemning it in a tweet.

The incident happened when students were leaving the school.

"A car bomb blast happened first, and then two more explosions occurred near the girls school in Kabul," said Ibrahim, a schoolteacher.

He added that the majority of victims are girls.

The attack was condemned by the Afghan government and some diplomatic missions in Kabul as an act of terror.