Construction workers at one of the 2010 South Africa World Cup stadiums launched a strike over pay on Monday, their union said.

"It is true that they are on strike. The details are still sketchy.

But a meeting with the strikers and the management is scheduled for Tuesday to look into the matter," George Ledwaba, a spokesman for the National Union of Mineworkers,said.

Stadium project manager Neil Founie said the workers downed tools over wages and bonuses, but insisted the project remained on track.

"We are on track on our completion date schedule. The project is at 72.4% of completion.

"So, we have enough time to complete the project before the end of July target date," he said.

Workers at the 46 000-seat Mbombela stadium have staged earlier strikes, most significantly in February last year to demand a near doubling of their wage.

Similar disputes have previously broken out at stadiums in Durban and Cape Town, but World Cup organisers say they are confident those projects will be complete on time.

Ten stadiums in nine cities will play host to the 2010 World Cup, the first time the tournament has been staged in Africa.