Petrobras began drilling on Monday, the same day it was granted a license after a five-year battle to explore for oil in the sensitive region, 500 kilometers (310 miles) from the mouth of the Amazon River.

The granting of the license angered activists who said it would undermine Brazil's hosting of the COP30 UN climate talks and poses a danger to a region rich in biodiversity off the coast of the world's largest tropical rainforest.

Groups representing environmentalists, Indigenous people, artisanal fishers and Afro-Brazilian communities filed a lawsuit on Wednesday "requesting the annulment of the license," they said in a statement.

They "also request an injunction immediately suspending drilling activities, under the risk of irreversible damage to the environment."

The lawsuit alleges that the licensing process did not study the potential impacts on Indigenous communities or Quilombolas -- communities of descendants of African slaves.

It also stated that Petrobras relied on outdated environmental modeling and data when presenting its plan in case of an oil spill.

Petrobras has said its models show that an oil spill at the offshore site "would not be likely to reach the coast" and there would be "no direct impact" on Indigenous communities.

According to the NGOs statement, their lawsuit demonstrates that in the case of an oil spill, 20 percent of the oil would sink and possibly affect the Great Amazon Reef System.

They also argue the process ignores the project's contribution to the climate crisis -- contradicting Brazil's commitments ahead of COP30.

Petrobras told AFP it had no comment for the moment on the lawsuit.