Police tell The Associated Press that the incident happened Tuesday afternoon at the Metropolitan Cathedral in Campinas, a city about 60 miles (100 kilometers) north of from Sao Paulo.
Catholic representatives worked to keep negotiations on track for a comprehensive deal to address global warming as the U.N. climate change conference entered its second and final week in Katowice, Poland.
The sisters argue that the Vatican commissioners sent to replace their superior general, who is also the niece of the order's founder, have no understanding of their way of life or spirituality.