The Catholic Church`s Pastoral Land Commission (CPT) had given the government a list of 125 activists and community leaders in the country`s northern Amazon states who have received death threats, urging authorities to provide protection in the most urgent cases.
"The government intends to work with the states to assess the most critical cases. We will look at it on a case-by-case basis whether to provide protection to those receiving the most threats," Barreto told reporters in Brasilia.
Community leader Adelino Ramos was shot dead Friday after ongoing work to denounce illegal logging, and farming leader Eremilton Pereira dos Santos was killed on Saturday.
Last Tuesday, the husband and wife environmental team of Jose Claudio Ribeiro da Silva and Maria do Espirito Santo da Silva were killed by gunmen in Brazil`s northern Amazon state of Para.
According to the group they worked for, the pair had also been receiving death threats over their work to preserve the rainforest in the state, and prevent illegal deforestation for charcoal production and to clear land for cattle pastures.
Brazil has 5.3 million square kilometers of jungle and forests -- mostly in the Amazon river basin -- of which only 1.7 million are under state protection.
The rest is in private hands, or its ownership is undefined.