A magistrate in the Spanish capital on Thursday ordered the bus to stay off the road until its controversial full-length advertisement is removed.

The orange-and-white billboard, which states: "Boys have penises, girls have vulvas. Don't let them fool you. If you're born a man, you're man. If you're a woman, you will continue to be so," suddenly appeared on the streets of Madrid on Monday.

Widespread complaints from the public led to the vehicle, which was paid for by the Catholic organization "Hazte Oir" (Make Yourself Heard), being temporarily immobilized on Wednesday.

Prosecutors acting on behalf of Madrid's City Hall went to court on Thursday to extend the ban, telling the judge that the ad was at risk of perpetuating a hate crime and of disturbing the peace, Spanish newspaper "El Pais" reported.

Although the magistrate disagreed that it amounted to a hate crime but said it sought to erode the "dignity" of those with a "different" sexual orientation, the paper said.

Church group behind the campaign

In a statement, the Hazte Oir said it designed the contentious campaign to speak out against teaching schoolchildren about gender and sexual diversity.

Before the vehicle was impounded, the group had planned a nationwide bus tour of Spanish cities.

The bus appeared to counter an earlier ad campaign by transgender supporters, whose bus shelter billboards stated: "There are girls with penises and boys with vulvas.”

Hazte Oir has previously campaigned against abortion and lesbian, gay, bisexual or transgender LGBT rights.

Spanish politicians were quick to denounce the group's latest controversial message.

"Those from HazteOir may have penises and vaginas, but they clearly don't have a brain, nor do they have a heart," Pablo Iglesias, leader of the far-left Podemos party, said in a television interview.

Javier Maroto, a gay lawmaker for the ruling conservative Popular Party, also slammed a project he labeled a "disgraceful campaign of hate" against people who are LGBT.

But Hazte Oir was cited by "El Pais" as claiming the bus had been "hijacked."

A small group of their supporters protested the vehicle's seizure on Wednesday.

mm/rg (AP, AFP, dpa, El Pais)