The mother of a dead US Muslim soldier has hit back at presidential hopeful Donald Trump for questioning her silence during a speech by her husband.
Ghazala Khan said Mr Trump was ignorant about Islam and that he didn't know the meaning of the word sacrifice.
Her husband Khizr Khan attacked the Republican nominee in an emotional speech to the Democratic National Convention on Thursday.
Mr Trump later suggested Mrs Khan may not have been allowed to speak.
The couple's son, US Army Capt Humayun Khan, was killed by a car bomb in 2004 in Iraq at the age of 27.
In an opinion article for the Washington Post, Mrs Khan said her husband had asked her if she wanted to speak at the convention but she had been too upset.
"Walking on to the convention stage, with a huge picture of my son behind me, I could hardly control myself. What mother could? Donald Trump has children whom he loves. Does he really need to wonder why I did not speak?" she wrote.
"When Donald Trump is talking about Islam, he is ignorant. If he studied the real Islam and Koran, all the ideas he gets from terrorists would change, because terrorism is a different religion."
She added: "Donald Trump said he has made a lot of sacrifices. He doesn't know what the word sacrifice means."
Mrs Khan said that although she did not speak, "all the world, all America, felt my pain".