An explosion outside the Shama-e Hedayat school and private education center in the Dasht-e Barchi area of western Kabul on Monday evening injured at least 52 students, mostly girls, according to local sources.

Witnesses said the injured were taken to Esteqlal, Alami and Emergency hospitals for treatment.Khalid Zadran, a spokesman for Kabul police, said the explosion was caused by a hand grenade, but the exact number of casualties had not yet been confirmed.

The incident has renewed concerns over the security of educational institutions in Kabul, particularly those serving the city`s predominantly Shiite Hazara community.During Afghanistan`s previous republican government, schools and educational centers in Shiite areas were repeatedly targeted in attacks, causing scores of civilian casualties.

Monday`s blast has raised fears among residents that similar attacks could recur, while also increasing concerns about the protection of students and the security situation in western Kabul.