The stories are illustrated with characters from ethnically diverse backgrounds. The Muslim girl, aged three or four, is called Razmi and is always shown wearing a headscarf. Razmi is seen indoors in the home of a Chinese girl and on outings, The Times reported.
The Children's Traffic Club London, promoted by Transport for London or TFL, has recruited more than 66,000 children across city to run the campaign. the capital. TFL, chaired by Sadiq Khan, the capital's Labour mayor, has apologised and said it would stop using the images, the report said.
The books were introduced under his Conservative predecessor Boris Johnson, now the foreign secretary, in 2015. Gina Khan, an advocate of Muslim women's equality, was quoted as saying, "You are sexualising a four-year-old girl. It is as simple as that. The reason a female is covered is so men don't look at her. How can you integrate in society if you have a four-year-old girl wearing a hijab?"
Shaista Gohir, chairwoman of the Muslim Women's Network UK charity, said, "It's like trying to get that child to try to grow up far too quickly. A child needs to be treated like a child."
Dame Louise Casey, the government's integration tsar, intervened in a row in Birmingham this year when a Catholic school came under pressure to let a four-year-old girl wear a Muslim headscarf. She has expressed concern that "time and again I found it was women and children who were the targets of these (kind of) regressive practices" against the vulnerable.
A TFL spokeswoman was quoted as saying, "We apologise for any offence caused by this content and we will not use these designs in future."