In the second incident of its kind this year, two workers on a construction project operated by Brazil's Petrobras died as a result of drowning, a union said.

Two contract workers drowned after the scaffolding they were working on at the end of a pier collapsed at the Barra do Riacho terminal, operated by a division of Petroleo Brasileiro, known also as Petrobras, the union Federation of Oil reported.

The union, known by its Portuguese initials FUP, said emergency workers took about an hour to recover the bodies from the water. Both contract workers were tied in to the platform with security belts, even though the work permit called only for life vests.

Both workers were dragged into the water when concrete at the pier gave way, the union said.

Six contractors died as a result of an explosion on the floating production storage and offloading vessel Cidade de Sao Mateus off the coast of Brazil in February. Brazilian producer Petrobras deployed the vessel at the oil-rich Santos Basin off the country's coast in mid-November.

In April, Petrobras said it was working to move past a "sad chapter" after taking a massive loss in a graft scandal, its top executive said. In its first audited statement in nearly a year, the company said it was writing off around $17 billion, of which $2.1 billion was due to alleged graft.

Petrobras last week published a management plan through 2019 that reflects the downturn in crude oil prices. The Brazilian company cut overall spending plans by 40 percent, but allocated 84 percent of that to exploration and production, a 14 percent increase from the previous year.