Several casualties were feared after two bombs rocked a boys' school in a Shia Hazara neighborhood of the Afghan capital on Tuesday, police said, with social media showing grisly images of dead and wounded at the scene.

Kabul police spokesman Khalid Zadran told AFP that two improvised explosive devices were placed outside the Abdul Rahim Shahid high school in the capital's western Dasht-e-Barchi neighborhood.

He earlier tweeted that three blasts had rocked the school, which is in an area mainly inhabited by the Hazara community and has been previously targeted by the jihadist Islamic State group.

Tuesday's blasts occurred as students were coming out of their morning classes, a witness told AFP.

Victims were taken to hospital, but Taliban fighters kept journalists from the premises.

Attacks on public targets have largely diminished since the Taliban seized power in August last year, but the jihadist Islamic State group continues to operate across the country.

Taliban officials insist their forces have defeated IS, but analysts say the jihadist group is a key security challenge to the hardline Islamists who now rule Afghanistan.

In May last year at least 85 people -- mainly girl students -- were killed and about 300 were wounded when three bombs exploded near their school in Dasht-e-Barchi.

No group claimed responsibility, but in October 2020 IS claimed a suicide attack on an educational centre in the same area that killed 24, including students.

In May 2020, the group was blamed for a bloody attack on a maternity ward of a hospital in the neighbourhood that killed 25 people, as well as new mothers.