Petrobras said it was “surprised” by a regulator’s decision that prevented the Brazilian state-controlled company from conducting drilling operations in the environmentally sensitive Foz do Amazonas basin in the country’s northern equatorial margin.

Earlier this week, Brazil’s environmental agency Ibama rejected a Petrobras application to spud the Morpho wildcat in Block FZA-M-59 due to a set of “technical inconsistencies” on the project, confirming an earlier report on the topic by Upstream.

Ibama claimed Petrobras did not provide assurances for safe exploration activities in the region and argued a more in-depth environmental assessment of sedimentary basins (AAAS) study was needed to identify the risks associated to drilling in Foz do Amazonas.