The deed appears to have been directed against the school's leadership.
(The principal) Hamid ul Haq has been killed, and he was apparently the target of the suicide bomber, says the local police chief Abdul Rasheed.
He adds that at least five people were killed in total, and over ten were injured.
The affected school near Peshawar is called Dar-ul-Uloom Haqqania, but has been called the "jihad university" since many students who became extremists and got prominent positions among the hard-line Taliban have attended there. Among them is the legendary mullah Omar, who long led the Taliban in neighboring Afghanistan.
