"We must speak up before these acts occur, work to ensure that they do not happen again, and keep our courage to continue to resist the ongoing cruelty and barbarism of the Taliban," Bush said, writing in the Washington Post on Wednesday. "Malala Yousufzai refused to look the other way. We owe it to her courage and sacrifice to do the same."

The singer Madonna said, during a Wednesday night concert in Los Angeles, that Malala's story made her cry and exclaimed, "Support education! Support women!" As she performed a striptease, Madonna "turned her back to the audience to reveal the name 'Malala' stenciled across it," according to The Hollywood Reporter.

"This song is for you, Malala," she said, and then sang "Human Nature."

Malala wrote about her life in Swat Valley, a hotbed of militant activity.

The valley near the Afghanistan border once attracted tourists to Pakistan's only ski resort, as well as visitors to the ancient Buddhist ruins in the area. But that was before militants -- their faces covered with dark turbans -- unleashed a wave of violence.

They demanded veils for women, beards for men and a ban on music and television. They allowed boys' schools to operate but closed those for girls.

It was in this climate that Malala reached out to the outside world through her blog posts.

"I have the right of education," Malala said in a CNN interview last year. "I have the right to play. I have the right to sing. I have the right to talk. I have the right to go to market. I have the right to speak up."

Malala also encouraged other young people to take a stand against the Taliban -- and to not hide in their bedrooms. "God will ask you on the day of judgment where were you when your people were asking you, when your school fellows were asking you, and when your school was asking you (why) I am being blown up."

Mian Iftikhar Hussein, Swat Valley's provincial information minister, said he was declaring a bounty of $100,000 for the capture of the culprits in the attempt on Malala's life.