Construction workers refurbishing the famed Maracana Stadium for the 2014 World Cup went on strike after one of their colleagues was badly burnt and suffered leg injuries in an on-site explosion.

“We must improve our working conditions which are not ideal. We’ll only return to work when our demands have been heard,” union director Romildo da Silva told Reuters.

Hundreds of workers held a demonstration outside the stadium to draw attention to their demands, which also include higher pay and health care. Up to 1,500 people work on the stadium in rotating shifts.

The Maracana will stage Confederations Cup matches in 2013 and is expected to host the World Cup final a year later.