Around 300 federal and state officers and environmental ministry agents deployed in and around the northern town of Tailandia, 250 kilometers (150 miles) from the city Belem, in an operation dubbed "Arc of Fire" that began Tuesday.
"This action is not wrapping up -- it's only the first step," one official taking part in inspections of logging operators told AFP.
The units were deploying in trucks with rifles, automatic weapons, pistols and teargas launchers at the ready to stave off any repeat of the opposition by thousands of locals that put a stop to a previous, smaller anti-logging operation early this month.
That preceding action resulted in the seizure of 13,000 square meters of lumber that will go to building and fence construction in deforested zones, a spokesman for the environmental ministry in Para state, Douglas Martinelli, said.
Authorities said 70 of the 140 sawmills in Tailandia had been inspected. They expected the others would be gone over within the next three weeks and that up to 50,000 square meters more of wood would be confiscated.
The second phase of the campaign is to kick in at the beginning of April when 1,000 agents will widen their inspections to 36 towns and hamlets in the three Brazilian states that have suffered the worst deforestation: Para, Mato Grosso and Rondonia.
The Brazilian government has allocated 200 million reais (120 million dollars) for the operation.