A group of workers helping to renovate one of the stadiums for the 2014 World Cup went on strike Wednesday, demanding higher salaries and improved conditions.

About 160 of the nearly 400 workers helping upgrade the Mineirao Stadium in Belo Horizonte stopped working. 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 to $755. The renovation at the Mineirao is expected to cost nearly $470 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.