A bullfighting school that trains youngsters to kill calves for entertainment has defied a mounting wave of outrage by having teenagers slaughter 24 of the animals in just four days.

Comedian Ricky Gervais joined the chorus of anger after four calves were massacred by youths as part of their matador training last month, branding the bullfighting schools 'c*** academy'.

But now a school in Colmenar Viejo has doubled down on the disturbing practice by having 24 of the helpless creatures killed by its students within just four days.

Footage captured by activists from Animal Guardians and La Tortura No Es Cultura (Torture Is Not Culture) show the bullfighters are clearly teenagers.

A young bullfighter launching a swords known as a banderillas as a calf during the training event in Spain

As the calves lay dying their ears are severed and a young trainee matador holds it aloft at the bullring in Colmenar Viejo

The bullring is almost empty, but children are among those watching, with one boy seen recording the slaughter on his tablet computer.

Some of the younger children are later presented with ears carved from the dying animals as a gruesome trophy.

Marta Esteban of Animal Guardians said the exact ages of the would-be matadors could not be determined, but some youths start training at just 14.

She said: 'They usually start killing animals from 14 years old onwards and they usually stay in bullfighting schools until they are 18, although some stay until they are 21.

'This event violates the right of children and adolescents to live in an environment free of violence and it is imperative that something be done about it.'

Young trainee matadors paraded around the ring holding severed calf ears

Young matadors were seen competing in the 'becerradas' events or calf-fights, with even younger children in the crowd watching

The calf-fights, known in Spanish as becerradas, are considered 'practical classes' by the bullfighting schools.

Calves are often used when inexperienced matadors or untrained guests enter the bullring, because they are less of a danger to humans.

However, calves feel more keenly the agony of the swords and banderillas – those they face are less experienced and the blows are less likely to be fatal, prolonging the torture.

Now the activists are launching an international petition to ensure the calf-fights are banned from the country.

Carmen Ibarlucea, president of La Tortura No Es Cultura, said: 'It is inconceivable that these acts of extreme violence towards sentient beings can be considered a form of entertainment.

'They are an atrocity and should be banned. We ask people to sign our petition and write to the city council of Colmenar Viejo asking for the end of these spectacles.'