Petrobras put 12 offshore oil rigs back into operation on May 26 following a stoppage on two days earlier that was due to a second unexplained oil spill in a week, officials said. Petrobras resumed operations after concluding the oil in the slick was different to that produced at the rigs, a Petrobras spokesman said. "All rigs, underwater pipelines and systems are in perfect order," the spokesman said. Petrobras, which has experienced a series of oil spills in the past two years, has said production losses from the stoppage, which occurred in the northern zone of the Campos oil field, were 120,000 bpd - nearly nine percent of Brazil's overall daily output. Natural gas output losses were 830,000 cubic meters a day. A week earlier, a similar stoppage occurred in the same area.