At least two workers have died in an accident at Sao Paulo's Itaquerao Stadium, one of the 12 stadiums that will host games in next year's football World Cup.

Television footage of the accident on Wednesday showed a 500-tonne metal structure cut through the stadium's outer walls, destroying some of the seats on the east side of the venue and crashing into a massive LED panel that runs across the stadium's facade.

The crane accident delays the completion of the almost-ready stadium and may hinder the Latin American country's plans to abide by FIFA's deadline of December 31 to finish all 12 World Cup venues.

While a fire department official said that three people had died in the accident, former Corinthians President Andres Sanchez told a news conference that only two people were confirmed dead. Local media reported a third person was seriously injured.

Brazil has encountered a number of accidents as it prepares for the world's biggest football event. One worker died during construction of a stadium in the capital Brasilia last year and another in the Manaus venue in March.

The $360-million Sao Paulo stadium will seat nearly 70,000 people for the opener on June 12, in which Brazil will play. About 20,000 seats will be temporary and installed only for the World Cup.

Source: Al Jazeera and agencies