At least 126 people, mostly children, have been killed in a Taliban assault on an army-run school in the Pakistani city of Peshawar, officials say.
All six of the militants who entered the building are said to have been killed, at least one of them in a suicide blast.
However, the army has not declared the operation over. Most of the 500 students have been evacuated.
The attack is being seen as one of the worst so far in Pakistan.
The BBC's Shahzeb Jillani in Karachi says the militants appear to have been intent on killing as many students as possible - rather than taking hostages, as initially thought.
Thousands of Pakistanis have been killed in militant violence in recent years - but the latest attack has caused unprecedented shock.
A spokesman for the militants told BBC Urdu that the school had been targeted in response to army operations.
Hundreds of Taliban fighters are thought to have died in a recent military offensive in North Waziristan and the nearby Khyber area.