Protests are continuing in South Africa after a video emerged showing four white university students humiliating a group of black cleaners.

At least 28 students have been arrested during the demos at the University of the Free State, where the video was made.They are accused of making threats against white members of staff.

The arrests have added to the tension on the Bloemfontein campus, which is still reeling from the tape's release.

In it, the footage appears to show white students forcing the black workers to eat food contaminated with urine.

"We are calling for a national day of protest," Tshitiso Nkgwedi, a representative of the Student's Congress of South Africa announced during a march.

Most of those joining the demonstrations were young children when racist rule ended in South Africa.

But 14 years on, they are singing the songs of the apartheid struggle and denouncing what they claim is institutionalised discrimination at the once white-dominated university.

The college is now 60% black, but the halls of residence are still largely segregated according to race.

The Reitz hostel, where the white students who made the tape were living, has 110 students and just eight of them are black.

"As Afrikaaners, we feel threatened here," Pieter Odendal said, insisting that far from being racist, white residents are actually the victims of racism in the new South Africa.

Hostel boss Chris Diepenaar agreed: "As a white man, you can't get a job because those positions are given to people with a different skin colour."

It is a view shared by a growing number of white South Africans, both on campus and beyond, who feel marginalised by the ANC's policy of affirmative action and threatened by the high rates of violent crime."We understand their concerns," Professor Frederick Fourie, the Rector of the university said.

"Afrikaaners feel like they're been squeezed in South Africa, and the hostel is a piece of territory they want to protect."

The black students who come from communities plagued by poverty, as well as the same crime the whites complain of, have little sympathy.

"It's the same here for all of us, we're all victims," one girl said.

As a snapshot of the new South Africa, the situation at the university is not encouraging. But the Rector is philosophical.

"People thought after Mandela that the race issues were over in South Africa, but every process of social change has its problems," he said.