Pakistan's interior minister, Rehman Malik, said the authorities had identified the two gunmen behind the shooting, but they had not been captured.
Police officials in the Swat Valley, where the attack took place, said that they had rounded up about 70 people for questioning, including employees of Malala's school and the bus driver, and that some of them had been formally arrested.
A 15-year-old girl who was wounded alongside Malala described how easily the Taliban had been able to attack the school bus.
"A young man in his early 20s approached the bus and asked for Malala," the girl, Kainat Riaz, said in an interview at her family's home in Swat. "Then he started firing."
The fate of Malala, who has become a symbol of defiance of the Taliban's extremist ideology, has gripped Pakistan, reports The New York Times.
Television stations have provided intensive coverage of her medical treatment, and leaders from across the nation's political and religious spectrums have united in condemning the attack.
