KABUL: An explosion near a school in the Afghan capital Kabul on Saturday killed at least 25 people and wounded dozens more, the interior ministry said.

Ministry spokesman Tariq Arian said at least 52 people, most of them students, were injured in the blast.

He did not specify the cause or the target of the explosion.

Ghulam Dastagir Nazari, spokesman for the health ministry, said 46 people had been taken to hospitals so far.

Kabul is on high alert since Washington announced plans last month to pull out all U.S. troops by Sept. 11. with Afghan officials saying Taliban have stepped up their attacks across the country.

No group has claimed responsibility for Saturday's blast.

It took place in western part of Kabul, a heavily Shi'ite Muslim neighbourhood that has frequently been attacked by Islamic State militants over the years.