JOHANNESBURG, South Africa (AFP) — Fresh protests by stadium workers erupted yesterday, adding to a sombre tone at the World Cup as Nelson Mandela mourned his great-grand-daughter and the host reeled from a stunning defeat.

Hundreds of mourners joined the Mandela family at the funeral for 13-year-old Zenani Mandela, who died in a car accident on the eve of the World Cup after a concert in Soweto.

Heart-broken, 91-year-old Mandela pulled out of the the World Cup opener. The funeral was his first public appearance since February, when he went to parliament to mark the 20th anniversary of his release from an apartheid prison.

The service at a private school in Johannesburg was filled with song, tears and sometimes laughter at memories of the young girl, who beamed with delight at meeting Real Madrid star Cristiano Ronaldo on her birthday two days before her death.

But across the country in Cape Town, frustrations again boiled over among stadium security guards who clashed with police for the second time this week in a dispute over their pay.

Police fired a stun grenade and rubber bullets to break up the protest by 200 security guards outside the office of Stallion Security, according to the company contracted to provide stewards at four World Cup stadiums.

“They were warned that it’s an illegal gathering. They were given time to disperse and they didn’t. After several attempts we used a stun grenade and rubber bullets to disperse the crowd,” said police spokesman Andre Traut.

“A number of security guards were then arrested for illegal gathering.”

Police were forced to take over security at four World Cup stadiums after wildcat strikes by stewards.

“If anybody else disrupts any other stadium we are ready, in the shortest possible time, to take over that stadium,” police chief Bheki Cele said.

“There shall be no disruption of 2010 FIFA World Cup matches here in South Africa.”

World Cup boss Danny Jordaan said he was satisfied that the strike disturbances were under control, as police had quickly stepped in.

“I think they’ve done an incredible job. In Cape town within three hours, everything was in place and the game started on time,” he said.

“We just had another meeting with police yesterday and we’re satisfied everything is in place.”

After winning its World Cup bid six years ago, South Africa has fended off accusations about its ability to host the tournament with problems mounting after a triumphant opening.

Bus drivers also staged a brief wildcat strike Monday, while protesters marched Wednesday in Durban against government spending on the tournament.

Stallion Security’s security contracts were cancelled after the steward strikes spread, but the company said the local organising committee had played a role in setting wages.

“The Psira (Private Security Industry Regulatory Authority) linked rates were determined at the LOC’s insistence,” said chief executive Clive Zulberg, the Sapa news agency reported.

The national spirit also dampened after South Africa’s 3-0 thrashing from Uruguay, heightening fears that the host might become the first in World Cup history not make it to the second round.

But Jordaan said supporters will hope again and return to blowing vuvuzelas, the controversial trumpets whose loud buzz has been the trade-mark of the tournament.