Brazilian authorities said no casualties were reported and measures to gauge the potential environmental damage were underway after the Liberian-flagged oil tanker Minerva Rita, carrying 18,000 m³ of Naphtha and 8,499 m³ of gasoline, had her hull damaged after running aground on Monday about 170 kilometers from the State's capital down the Amazon River en route from Manaus to a refinery in Itacoatiara.