A group of workers went on strike Wednesday at the construction site for one of the stadiums that could host the 2014 World Cup opener, demanding higher salaries and improved conditions.

About 160 of the nearly 400 workers helping upgrade the Mineirao Stadium in Belo Horizonte stopped working to protest poor conditions and low wages.

Local organizers said in a statement that constructors have been following union regulations, and that a commission has been created to negotiate with the workers.

They said that work was not completely halted because of the strike.

The private Agencia Estado news service says workers want to raise their monthly salaries from about $580 (?400) to $755 (?520).

The renovation at the Mineirao is expected to cost nearly $470 million (?325 million).

Belo Horizonte is one of the cities vying to host the opening match. Others include the nation's capital, Brasilia, and Sao Paulo, South America's biggest city.